Phosphor-containing film and backlight unit

ABSTRACT

A phosphor-containing film suppresses deterioration of a phosphor and generation of luminescent spots and the reduction in luminance, and a backlight unit. The phosphor-containing film includes: a phosphor-containing layer having a resin layer which has oxygen impermeability and discrete concave portions, and fluorescent regions arranged in the concave portions, and a first substrate film laminated on one surface of the phosphor-containing layer and a second substrate film laminated on the opposing surface, in which the fluorescent regions contain the phosphor that deteriorates through a reaction with oxygen, and a binder, the first substrate film includes a support film and an inorganic layer provided on a surface of the support film on a side facing the phosphor-containing layer, the resin layer has a modulus of elasticity of 0.5 to 10 GPa, and a thickness of the bottom of the concave portion of the resin layer is 0.1 to 20 μm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of PCT International Application No.PCT/JP2017/039951 filed on Nov. 6, 2017, which claims priority under 35U.S.C. § 119(a) to Japanese Patent Application No. 2016-217583 filed onNov. 7, 2016 and Japanese Patent Application No. 2016-232970 filed onNov. 30, 2016. Each of the above applications is hereby expresslyincorporated by reference, in its entirety, into the presentapplication.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a phosphor-containing film containingphosphors that emit fluorescence upon irradiation with excitation lightand a backlight unit comprising the phosphor-containing film as awavelength converting member.

2. Description of the Related Art

Applications of a flat panel display such as a liquid crystal display(LCD) as a space-saving image display device with low power consumptionhave been widespread year by year. Hereinafter, the liquid crystaldisplay is referred to as the “LCD”. In recent LCDs, further powersaving, an enhancement in color reproducibility, or the like is requiredas an improvement in LCD performance.

Along with power saving of LCD backlight, in order to increase the lightutilization efficiency and improve the color reproducibility, it hasbeen proposed to use a wavelength converting layer containing a quantumdot (QD, also referred to as a quantum point) that converts a wavelengthof an incidence ray and emits the wavelength-converted light, as aluminescent material (phosphor).

The quantum dot has a state of an electron whose movement direction isrestricted in all directions three-dimensionally. In the case wherenanoparticles of a semiconductor are three-dimensionally surrounded by ahigh potential barrier, the nanoparticles become quantum dots. Thequantum dot expresses various quantum effects. For example, a “quantumsize effect” is expressed in which a density of electronic states(energy level) is discretized. According to this quantum size effect,the absorption wavelength and luminescence wavelength of light can becontrolled by changing the size of a quantum dot.

Generally, such quantum dots are dispersed in a resin or the like, andused as a quantum dot film for wavelength conversion, for example, bybeing disposed between a backlight and a liquid crystal panel.

In the case where excitation light is incident from a backlight to afilm containing quantum dots, the quantum dots are excited to emitfluorescence. Here, white light can be realized by using quantum dotshaving different luminescence properties and causing each quantum dot toemit light having a narrow half-width of red light, green light, or bluelight. Since the fluorescence by the quantum dot has a narrowhalf-width, wavelengths can be properly selected to thereby allow theresulting white light to be designed so that the white light is high inluminance and excellent in color reproducibility.

Meanwhile, there are problems that quantum dots are susceptible todeterioration due to moisture or oxygen, and particularly theluminescence intensity thereof decreases due to a photooxidationreaction. Therefore, the wavelength converting member is configured insuch a manner that barrier films (gas barrier films) are laminated onboth main surfaces of a resin layer containing quantum dots which is awavelength converting layer containing quantum dots, thereby protectingthe resin layer containing the quantum dots. Hereinafter, the resinlayer containing the quantum dots is also referred to as a “quantum dotlayer”.

As one example, the barrier film has a configuration in which a barrierlayer exhibiting gas barrier properties is formed on a surface of asupport film such as a resin film.

However, merely protecting both main surfaces of the quantum dot layerwith barrier films has a problem in which moisture or oxygen enters fromthe end face not protected by the barrier film, and therefore thequantum dots deteriorate.

Therefore, it has been proposed to protect the entire periphery (theentire periphery of an end face) of the quantum dot layer with a barrierfilm.

For example, JP2010-061098A discloses a quantum point wavelengthconverting structure including a wavelength converting portioncontaining quantum points for wavelength-converting excitation light togenerate wavelength-converted light and a dispersion medium fordispersing the quantum points, and a sealing member for sealing thewavelength converting portion, in which the wavelength convertingportion is disposed between two sealing sheets which are sealingmembers, and the peripheries of the wavelength converting portion in thesealing sheets are heated and thermally adhered to each other, therebysealing the wavelength converting portion.

Further, JP2009-283441A discloses a light emitting device comprising acolor conversion layer (phosphor layer) for converting at least a partof color light emitted from a light source portion into another colorlight and a water impermeable sealing sheet for sealing the colorconversion layer, and discloses a color conversion sheet (phosphorsheet) in which penetration of water into the color conversion layer isprevented by a configuration where the sheet has a second bonding layerprovided in a frame shape along the outer periphery of the phosphorlayer, that is, so as to surround the planar shape of the colorconversion layer, and the second bonding layer is formed of an adhesivematerial having water vapor barrier properties.

Meanwhile, the quantum dot layer (a wavelength converting layercontaining quantum dots) used for LCDs is a thin film of about 50 to 350μm in thickness. There are problems that it is extremely difficult tocoat the entire end face of such a very thin film with a sealing sheetsuch as a barrier film, thereby leading to poor productivity.

Such problems occur not only in quantum dots, but also in aphosphor-containing film comprising a phosphor which reacts with oxygenand deteriorates.

On the other hand, in order to produce a phosphor-containing filmcontaining a phosphor such as a quantum dot with high productionefficiency, preferred is a method of sequentially carrying out a coatingstep and a curing step on a long film by a roll-to-roll method to form alaminated structure and then cutting the resulting structure to adesired size.

However, in the case of obtaining a phosphor-containing film of adesired size by cutting from this long film, the phosphor-containinglayer is again exposed to the outside air at the cut end face, so it isnecessary to take measures against entry of oxygen from the cut endface.

On the other hand, US2015/0048403A discloses an optical componentincluding two substrates and a phosphor-containing layer which has afluorescent member having a sealing material forming a plurality ofseparated regions and a fluorescent substance arranged in the separatedregion, and is laminated between the two substrates. The US2015/0048403Adiscloses that, the optical component is cut at the sealing materialportion, and so the sealed state of the fluorescent member can bemaintained even in the case where the optical component is cut.

SUMMARY OF THE INVENTION

Here, even in the case where the phosphor-containing layer is configuredto include a resin layer forming a plurality of separated regions(concave portions) and a fluorescent region arranged in the separatedregion, it was found that problems that a mold is brought into contactwith the barrier film and thus the barrier layer of the barrier film isdestroyed and moisture and oxygen easily intrude have occurred in thecase of using the mold for forming the concave-convex portions in theresin layer.

The present invention has been made in view of the above circumstances,and an object of the present invention is to provide aphosphor-containing film which contains a phosphor such as a quantumdot, is capable of suppressing the deterioration of the phosphor, and iscapable of suppressing degradation of durability due to a defect of thebarrier layer; and a backlight unit comprising the phosphor-containingfilm as a wavelength converting member.

As a result of extensive studies to achieve the foregoing object, thepresent inventors have found that the foregoing object can be achievedby taking a configuration in which a phosphor-containing film includes aphosphor-containing layer having a resin layer which has impermeabilityto oxygen and is provided with a plurality of discretely arrangedconcave portions, and a plurality of fluorescent regions, each of whichis arranged in the concave portion formed in the resin layer, and afirst substrate film laminated on one main surface of thephosphor-containing layer and a second substrate film laminated on theother main surface of the phosphor-containing layer, in which thefluorescent regions contain the phosphor that deteriorates through areaction with oxygen in the case of being exposed to oxygen, and abinder, the first substrate film includes a support film, and aninorganic layer provided on a surface of the support film on a sidefacing the phosphor-containing layer, the resin layer has a modulus ofelasticity of 0.5 to 10 GPa, and a thickness of a bottom of the concaveportion of the resin layer is 0.1 to 20 μm. The present invention hasbeen completed based on these findings.

That is, it has been found that the foregoing object can be achieved bythe following configuration.

(1) A phosphor-containing film comprising:

a phosphor-containing layer having a resin layer which hasimpermeability to oxygen and is provided with a plurality of discretelyarranged concave portions, and a plurality of fluorescent regions, eachof which is arranged in the concave portion formed in the resin layer,and a first substrate film laminated on one main surface of thephosphor-containing layer and a second substrate film laminated on theother main surface of the phosphor-containing layer, in which thefluorescent regions contain the phosphor that deteriorates through areaction with oxygen in the case of being exposed to oxygen, and abinder,

the first substrate film includes a support film, and an inorganic layerprovided on a surface of the support film on a side facing thephosphor-containing layer,

the resin layer has a modulus of elasticity of 0.5 to 10 GPa, and

a thickness of a bottom of the concave portion of the resin layer is 0.1to 20 μm.

(2) The phosphor-containing film according to (1), in which the secondsubstrate film includes a support film and an inorganic layer providedon a surface of the support film on a side facing thephosphor-containing layer, and the inorganic layer of the secondsubstrate film and the top surface of the concave portion of the resinlayer are not in contact with each other.

(3) The phosphor-containing film according to (1) or (2), in which adepth h of the concave portion of the resin layer is 10 to 80 μm, and awidth t between the adjacent fluorescent regions is 5 to 300 μm.

(4) The phosphor-containing film according to any one of (1) to (3), inwhich the resin layer has an oxygen permeability of 10 cc/(m²·day·atm)or less.

(5) The phosphor-containing film according to any one of (1) to (4), inwhich the first substrate film and the second substrate film have anoxygen permeability of 1 cc/(m²·day·atm) or less.

(6) The phosphor-containing film according to any one of (1) to (5), thephosphor-containing layer, the fluorescent region is surrounded by theresin layer and a fluorescent region including a phosphor which hasdeteriorated through a reaction with oxygen by exposure to oxygen.

(7) A backlight unit comprising:

a wavelength converting member including the phosphor-containing filmaccording to any one of (1) to (6); and at least one of a blue lightemitting diode or an ultraviolet light emitting diode.

According to the present invention, it is possible to provide aphosphor-containing film which contains a phosphor such as a quantumdot, is capable of suppressing damage to the barrier layer of thebarrier film, and is capable of suppressing the deterioration of thephosphor due to oxygen or the like even in the case of using the moldfor forming the concave-convex portions, and a backlight unit comprisingthe phosphor-containing film as a wavelength converting member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view schematically showing an example of aphosphor-containing film of the present invention.

FIG. 2 is a plan view of the phosphor-containing film of FIG. 1.

FIG. 3 is a cross-sectional view of the phosphor-containing film of FIG.1.

FIG. 4 is a view for explaining a depth h of a concave portion in afluorescent region and a width t between adjacent fluorescent regions.

FIG. 5 is a plan view showing another example of a plan view pattern ofthe fluorescent region.

FIG. 6 is a plan view showing still another example of the plan viewpattern of the fluorescent region.

FIG. 7 is a view for explaining a method of specifying a contour of thefluorescent region.

FIG. 8A is a plan view schematically showing another example of thephosphor-containing film of the present invention.

FIG. 8B is a cross-sectional view taken along a line B-B of FIG. 8A.

FIG. 8C is a cross-sectional view taken along a line C-C of FIG. 8A.

FIG. 9A is a plan view schematically showing still another example ofthe phosphor-containing film of the present invention.

FIG. 9B is a cross-sectional view taken along a line B-B of FIG. 9A.

FIG. 10A is a plan view schematically showing still another example ofthe phosphor-containing film of the present invention.

FIG. 10B is a cross-sectional view taken along a line B-B of FIG. 10A.

FIG. 11 is a schematic view for explaining an example of a method forproducing the phosphor-containing film of the present invention.

FIG. 12 is a schematic view for explaining another example of the methodfor producing the phosphor-containing film of the present invention.

FIG. 13 is a cross-sectional view of a schematic configuration of anexample of a backlight unit comprising the phosphor-containing film as awavelength converting member.

FIG. 14 is a cross-sectional view of a schematic configuration of anexample of a liquid crystal display comprising the backlight unit.

FIG. 15 is a conceptual diagram for explaining an example of thephosphor-containing film of the present invention.

FIG. 16 is a conceptual diagram for explaining another example of thephosphor-containing film of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a phosphor-containing film and a backlight unit comprisingthe phosphor-containing film according to embodiments of the presentinvention will be described with reference to the accompanying drawings.In the drawings of the present specification, the scale of each part isappropriately changed for easy visual recognition. In the presentspecification, the numerical range expressed by using “to” means a rangeincluding numerical values described before and after “to” as a lowerlimit value and an upper limit value, respectively.

Further, in the present specification, the term “(meth)acrylate” refersto at least one or any one of acrylate or methacrylate. The same appliesto “(meth)acryloyl” and the like.

<Phosphor-Containing Film>

The phosphor-containing film according to the embodiment of the presentinvention is a phosphor-containing film including:

a phosphor-containing layer having a resin layer which hasimpermeability to oxygen and is provided with a plurality of discretelyarranged concave portions, and a plurality of fluorescent regions, eachof which is arranged in the concave portion formed in the resin layer;and

a first substrate film laminated on one main surface of thephosphor-containing layer and a second substrate film laminated on theother main surface of the phosphor-containing layer,

in which the fluorescent regions contain the phosphor that deterioratesthrough a reaction with oxygen in the case of being exposed to oxygen,and a binder,

the first substrate film includes a support film, and an inorganic layerprovided on a surface of the support film on a side facing thephosphor-containing layer,

the resin layer has a modulus of elasticity of 0.5 to 10 GPa, and

a thickness of a bottom of the concave portion of the resin layer is 0.1to 20 μm.

FIG. 1 is a perspective view schematically showing an example of aphosphor-containing film 1 according to the embodiment of the presentinvention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is across-sectional view of FIG. 1. In FIG. 1, a second substrate film 20 isindicated by a broken line and a phosphor-containing layer 30 isindicated by a solid line for the purpose of explanation.

The phosphor-containing film 1 according to the embodiment of thepresent embodiment comprises a first substrate film 10, aphosphor-containing layer 30 in which a plurality of regions 35containing phosphors 31 which deteriorates by being reacted with oxygenupon exposure to oxygen are discretely arranged on the first substratefilm 10, and a resin layer 38 having impermeability to oxygen isdisposed between the discretely arranged regions 35 containing phosphors31, and a second substrate film 20 disposed on the phosphor-containinglayer 30. Hereinafter, the region 35 containing the phosphors 31 may bereferred to as a fluorescent region 35 in some cases, and the resinlayer 38 having impermeability to oxygen may be referred as the resinlayer 38 in some cases.

In other words, the phosphor-containing layer 30 has a configurationhaving a resin layer 38 and a fluorescent region 35, in which aplurality of concave portions are discretely formed in the resin layer38, and the fluorescent region 35 is arranged in the concave portion ofthe resin layer 38.

In the present specification, the phrase “a plurality of regionscontaining phosphors . . . are discretely arranged on the firstsubstrate film” means that, as shown in FIGS. 1 and 2, in the case ofbeing viewed from the direction perpendicular to the film surface (mainsurface) of the first substrate film 10 (in plan view), a plurality offluorescent regions 35 are disposed in isolation without contacting eachother in the two-dimensional direction along the film surface of thefirst substrate film 10. Furthermore, the main surface means the maximumsurface of a sheet-shaped object.

In the example shown in FIG. 1, the fluorescent regions 35 are in theform of a cylinder (disk), and each fluorescent region 35 is isolatedlysurrounded by a resin layer 38 having impermeability to oxygen in thetwo-dimensional direction along the film surface of the first substratefilm 10, and the penetration of oxygen from the two-dimensionaldirection along the film surface of the first substrate film 10 into theindividual fluorescent regions 35 is blocked.

In the present specification, the phrase, “having impermeability tooxygen” means that an oxygen permeability is 10 cc/(m²·day·atm) or less.The oxygen permeability of the resin layer having impermeability tooxygen is more preferably 1 cc/(m²·day·atm) or less and still morepreferably 1×10⁻¹ cc/(m²·day·atm) or less.

The phrase “having impermeability” and the phrase “having barrierproperties” in the present specification are used synonymously. That is,in the present specification, a gas barrier means having impermeabilityto a gas, and a water vapor barrier means having impermeability to watervapor. Further, a layer having impermeability to both of oxygen andwater vapor is referred to as a “barrier layer”.

In the phosphor-containing film 1 according to the embodiment of thepresent invention, the fluorescent regions 35 are discretely arranged inthe two-dimensional direction. Therefore, as shown in FIG. 2, assumingthat the phosphor-containing film 1 is a part of a long film, whicheverportion is linearly cut as indicated by the broken line, the fluorescentregion 35 other than the fluorescent region 35 which is the cut point issurrounded by the resin layer 38, and thus can be kept in a sealedstate. In addition, the fluorescent region 35 that has been cut andexposed to outside air loses its function as an original phosphor, butthe deactivated fluorescent region becomes a resin layer that protectsthe fluorescent region 35 not exposed to outside air from the outsideair.

Here, in the phosphor-containing film 1 according to the embodiment ofthe present invention, the first substrate film 10 is laminated on onemain surface of the phosphor-containing layer 30, and comprises thesupport film 11 and the barrier layer 12. In addition, as conceptuallyshown in FIGS. 15 and 16, the barrier layer 12 is provided on thesurface of the support film 11 on the side facing thephosphor-containing layer 30 and has the inorganic layer 52.

In the phosphor-containing film 1 of the embodiment of the presentinvention, the thickness b of the bottom of the concave portion of theresin layer 38 is 0.1 to 20 μm. In the present invention, the phrase“the thickness b of the bottom of the concave portion of the resin layer38 is 0.1 to 20 μm” means that, for example, in the case where thebarrier layer 12 is configured with the organic layer 50, the inorganiclayer 52 on the organic layer 50, and the organic layer 54 on theinorganic layer 52, as shown in FIG. 15, the distance from the surfaceof the organic layer 54, which is the surface of the barrier layer 12located on the phosphor-containing layer 30 side, to the bottom surfaceof the concave portion of the resin layer 38, that is, the fluorescentregion 35 filled in the concave portion is 0.1 to 20 μm. In addition, ina case where the barrier layer 12 is configured with the organic layer50 and the inorganic layer 52 on the organic layer 50 as shown in FIG.16, the phrase “the thickness b of the bottom of the concave portion ofthe resin layer 38 is 0.1 to 20 μm” means that the distance from thesurface of the inorganic layer 52, which is the surface of the barrierlayer 12 on the phosphor-containing layer 30 side, to the bottom surfaceof the concave portion of the resin layer 38, that is, the fluorescentregion 35 filled in the concave portion is 0.1 to 20 μm.

In a preferred aspect, in the phosphor-containing film 1 of theembodiment of the present invention, the distance between the inorganiclayer of the first substrate film on a side contacting thephosphor-containing layer and the top surface of the concave portion ofthe resin layer is 0.01 to 10 μm. Furthermore, In a preferred aspect, inthe phosphor-containing film 1 of the embodiment of the presentinvention, as shown in FIG. 4, assuming that the depth h of the concaveportion of the resin layer 38 where the fluorescent regions 35 arearranged is h and the width between the adjacent fluorescent regions 35,that is, the thickness t of the resin layer 38 is t, the depth h of theconcave portion of the resin layer 38 is 1 to 100 μm, and the width tbetween adjacent fluorescent regions 35 is 5 to 300 μm.

As described above, in order to produce a phosphor-containing filmcontaining a phosphor such as a quantum dot with high productionefficiency, preferred is a method in which a coating step and a curingstep are sequentially carried out on a long film by a roll-to-rollmethod to form a laminated structure which is then cut into a desiredsize. In the case where a phosphor-containing film of a desired size iscut from this long film, the phosphor-containing layer is exposed to theoutside air at the cut end face, so it is necessary to take measuresagainst the penetration of oxygen from the cut end face.

Therefore, by taking a configuration in which a layer (fluorescentregion) containing a phosphor such as a quantum dot is discretelyarranged in a plurality of regions and a resin layer serving as asealing material is arranged around the fluorescent region, it isconsidered to keep the sealed state of the fluorescent member even inthe case where the optical component is cut, by cutting the film at thepart of the resin layer at the time of cutting the phosphor-containingfilm.

As will be described later, the phosphor-containing film in which theregion containing the phosphor is discretely arranged is formed, as oneexample, by forming a curable coating film, which is a resin layer, onthe surface of the barrier layer (gas barrier film) having the inorganiclayer that forms the barrier layer, the surface being on a side of theinorganic layer, and forming a plurality of discrete regions (concaveportions) in the coating film using the mold then curing the coatingfilm to form the resin layer having a plurality of concave portions, andfilling the fluorescent region in the concave portion and laminating andattaching the barrier film on the resin layer.

However, according to the studies of the present inventors, even in thecase where the phosphor-containing layer is configured to include aresin layer forming a plurality of separated regions (concave portions)and a fluorescent region arranged in the separated region, it was foundthat problems that a mold is brought into contact with the barrier filmand thus the barrier layer (inorganic layer) is destroyed and moistureand oxygen easily intrude have occurred in the case of using the moldfor forming the concave portions.

In contrast, in the phosphor-containing film according to the embodimentof the present invention, the thickness b of the bottom of the concaveportion of the resin layer 38 in contact with the first substrate film10 is 0.1 to 20 μm.

Also, preferably, the depth h of the concave portion of the resin layer38 is 1 to 100 μm, and the width t between adjacent fluorescent regionsis 5 to 300 μm.

According to the studies of the present inventors, by setting thethickness b of the bottom of the concave portion of the resin layer 38to 0.1 μm or more, it is possible to suppress contact of the mold withthe support film 11 (inorganic layer) at the time of forming concaveportions (concavity-convexity) in the resin layer 38, and as a result,it is possible to seal the end portion while keeping the barrierproperty of the main surface of the wavelength converting member. Inaddition, it was also found that, by reducing the thickness b of thebottom of the concave portion of the resin layer 38 to 20 μm or less,reduction in quantum yield of the wavelength converting member due tolight absorption of the resin layer 38 can be minimized. From the aboveviewpoint, specifically, the thickness b of the bottom of the concaveportion of the resin layer 38 is more preferably 0.5 to 15 μm, and stillmore preferably 1 to 10 μm.

The thickness b of the bottom of the concave portion of the resin layer38 is obtained by cutting the concave portion of the phosphor-containingfilm with a microtome to form a cross section, observing the sectionwith a scanning electron microscope (SEM) or the like, and extractingten concave portions to measure the distances between the bottomsurfaces of the concave portions and the inorganic layer and average themeasured distances.

Furthermore, in the phosphor-containing film according to the embodimentof the present invention, the second substrate film 20 is laminated onthe main surface of the phosphor-containing layer 30 which is opposed tothe first substrate film 10, and comprises the support film 21 and thebarrier layer 22. Similar to the first substrate film 10, the secondsubstrate film 20 preferably has the barrier layer 22 provided on thesurface of the support film 21 on the side of the phosphor-containinglayer 30, and has an inorganic layer.

Here, in the phosphor-containing film of the embodiment of the presentinvention, it is preferable that the surface of the second substratefilm 20 on the phosphor-containing layer 30 side and the top surface ofthe concave portion of the resin layer 38 are not in contact with eachother, from the viewpoint of enhancing the adhesiveness between thesecond substrate film 20 and the phosphor-containing layer 30. Thesurface of the second substrate film 20 on the phosphor-containing layer30 side is the surface of the barrier layer 22, and in a case where thebarrier layer 22 is configured with an organic layer, an inorganic layerand an organic layer as shown in FIG. 15, it is the surface of theorganic layer which is the outermost layer, and in a case where thebarrier layer 22 is configured with an organic layer and an inorganiclayer as shown in FIG. 16, it is the surface of the inorganic layerwhich is the outermost layer.

Specifically, the distance between the surface of the second substratefilm 20 on the phosphor-containing layer 30 side and the top surface ofthe concave portion of the resin layer 38 is preferably 0.01 to 10 μm,more preferably 0.05 to 4 μm, and still more preferably 0.1 to 4 μm. Byensuring the distance between the surface of the second substrate film20 on the phosphor-containing layer 30 side and the top surface of theconcave portion of the resin layer 38 to a certain degree, it ispossible to ensure adequate adhesiveness between the second substratefilm 20 and the phosphor-containing layer 30, and by setting thedistance between the surface of the second substrate film 20 on the sideof the phosphor-containing layer 30 and the top surface of the concaveportion of the resin layer 38 to be a certain distance or less, it ispossible to maintain the sealing ability by the resin layer 38 andensure reliability accordingly.

Here, the distance between the surface of the second substrate film 20on the side of the phosphor-containing layer 30 and the top surface ofthe concave portion of the resin layer 38 is obtained by cutting aportion of the top surface of the phosphor-containing film (a portionother than the concave portion) with the microtome to form a crosssection, observing the section with the SEM or the like, and extractingten top surfaces to measure the distances to the top surfaces andaverage the measured distances.

Between the surface of the second substrate film 20 on the side of thephosphor-containing layer 30 and the top surface of the concave portionof the resin layer 38, other materials may be used for the fluorescentregion 35. An example of a material other than the fluorescent region35, includes a material formed by providing a pressure-sensitiveadhesive layer or thermocompression-bondable sealant layer on the secondsubstrate film 20, forming the resin layer 38 on the first substratefilm 10, filling the fluorescent region 35, and then bonding andpressing the second substrate film 20 by heat pressing and the like.

As described above, in the phosphor-containing film 1 according to theembodiment of the present invention, the first substrate film 10includes the inorganic layer 52, and the thickness b of the bottom ofthe concave portion of the resin layer 38 is 0.1 to 20 μm.

Furthermore, it is preferable that the second substrate film 20 includesan inorganic layer, the surface of the second substrate film 20 is notcontact with the top surface of the concave portion of the resin layer38, and the depth h of the concave portion of the resin layer 38 is 1 to100 μm, and the width t between adjacent fluorescent regions is 5 to 300μm.

Here, although the target chromaticity can be reached in the case wherethe height (film thickness) of the fluorescent region 35 is 1 μm ormore, since the influence of film thickness unevenness increases, it ispreferable to have a film thickness of a certain level or more. On theother hand, in the case where the film thickness of the fluorescentregion 35 is too large, the amount of light absorption increases andtherefore the initial luminance may decrease. From these viewpoints, theheight of the fluorescent region 35, that is, the depth h of the concaveportion is preferably 1 to 100 μm, more preferably 5 to 80 μm, and stillmore preferably 10 to 50 μm.

It is preferable that the width t between the adjacent fluorescentregions 35, that is, the width t of the resin layer 38 portion is madethin to prevent the resin layer 38 from being visually recognized. Onthe other hand, from the viewpoint of strength and durability, a certainwidth or more is required. From these viewpoints, the width t betweenadjacent fluorescent regions 35, that is, the width t of the resin layer38 portion is preferably 5 to 300 more preferably 10 to 200 μm, andstill more preferably 15 to 100 μm.

The depth h of the concave portion formed in the resin layer 38 isdetermined in such a manner that a portion of the concave portion of thephosphor-containing film is cut with a microtome to form a crosssection; the phosphor-containing layer is irradiated with excitationlight to cause the phosphor to emit light; in this state, this crosssection is observed with a confocal laser microscope; and ten concaveportions are extracted and the depth thereof is measured and themeasured values are averaged.

The width t (that is, the thickness of the resin layer 38 portion)between the adjacent fluorescent regions 35 is the shortest distancebetween the adjacent fluorescent regions 35, and is determined in such amanner that the phosphor-containing layer is irradiated with excitationlight to cause the phosphor to emit light; in this state, the surface isobserved from one surface of the phosphor-containing film using aconfocal laser microscope; at least 20 portions of the resin layer 38between the adjacent fluorescent regions 35 are extracted and the widththereof is read; and the average value of these read values iscalculated as the width t.

The ratio of the area of the fluorescent region 35 to the total area ofthe phosphor-containing layer 30 in plan view is calculated as follows.The phosphor-containing layer is irradiated with excitation light tocause the phosphor to emit light; in this state, the surface of thephosphor-containing film is observed from directly above using aconfocal laser microscope; and the ratio (area of fluorescentregion/geometric area) is calculated from the total area of thefluorescent region and the area of the visual field (geometric area) forthe visual field (5 places) of 30 mm×30 mm, thereby calculating theaverage value in each visual field (5 places) as the ratio of the area.

Here, the fluorescent region 35 is formed by dispersing the phosphors 31in a binder 33. In the case where the oxygen permeability of the binder33 is larger than the permeability of the resin layer 38 filled betweenthe fluorescent regions 35, that is, in the case where the binder 33tends to permeate oxygen, the effects of the present invention areparticularly remarkable.

Further, the first substrate film 10 and the second substrate film 20are preferably impermeable to oxygen and it is preferable to have alaminated structure of a support film (11, 21) and a barrier layer (12,22) having impermeability to oxygen as shown in FIG. 3.

In addition, the size and arrangement pattern of the fluorescent region35 are not particularly limited and may be appropriately designedaccording to desired conditions. In designing, geometric constraints forarranging the fluorescent regions spaced apart from each other in planview, allowable values of the width of the non-light emitting regiongenerated at the time of cutting, and the like are taken intoconsideration. Further, for example, in the case where the printingmethod is used as one of the methods for forming a fluorescent region tobe described later, there is also a restriction that printing cannot becarried out unless the individual occupied area (in plan view) is notless than a certain size. Furthermore, the shortest distance (width t)between adjacent fluorescent regions is required to be a distancecapable of achieving an oxygen permeability of 10 cc/(m²·day·atm) orless. In consideration of these factors, a desired shape, a size, andarrangement pattern may be designed.

In the above embodiment, the fluorescent region 35 is cylindrical and iscircular in plan view, but the shape of the fluorescent region 35 is notparticularly limited. The fluorescent region 35 may be a polygonal prismor a regular polygonal prism such as a quadrangular in plan view asshown in FIG. 5, or a hexagon in plan view as shown in FIG. 6. In theabove example, the bottom surface of the cylinder or the polygonal prismis disposed parallel to the substrate film surface, but the bottomsurface may not necessarily be disposed parallel to the substrate filmsurface. Further, the shape of each fluorescent region 35 may beamorphous.

In the case where the boundary between the binder 33 in the fluorescentregion 35 and the resin layer 38 being impermeable to oxygen and beingbetween the fluorescent regions 35 is not clear, as shown in FIG. 7, aline connecting the points on the outside (the side on which thephosphor 31 is not disposed) of the phosphor 31 e positioned at theoutermost position of the region where the phosphor 31 is closelydisposed is considered as the contour m of the fluorescent region 35(the boundary between the fluorescent region 35 and the resin layer 38).The position of the phosphor can be specified by irradiation of thephosphor-containing layer with excitation light to cause the phosphor toemit light, followed by observation with, for example, a confocal lasermicroscope or the like, whereby the contour m of the fluorescent region35 can be specified. In the present specification, the side of acylinder or a polygonal prism is allowed to meander like the contour inFIG. 7.

In the above embodiment, the fluorescent region 35 is periodicallydisposed in a pattern, but it may be non-periodic as long as the desiredperformance is not impaired in the case where a plurality of fluorescentregions 35 are discretely arranged. It is preferable that thefluorescent region 35 is uniformly distributed over the entire region ofthe phosphor-containing layer 30 because the in-plane distribution ofluminance is uniform.

In order to obtain a sufficient amount of fluorescence, it is desirableto make the region occupied by the fluorescent region 35 as large aspossible.

The phosphor 31 in the fluorescent region 35 may be of one kind or ofplural kinds. In addition, the phosphor 31 in one fluorescent region 35is regarded as one kind, and a region containing a first phosphor and aregion containing a second phosphor different from the first phosphoramong the plurality of fluorescent regions 35 may be disposedperiodically or non-periodically. The kind of the phosphor may be threeor more.

The phosphor-containing layer 30 may be formed by laminating a pluralityof fluorescent regions 35 in the thickness direction of the film. Suchan example will be briefly described with reference to FIGS. 8A to 10B.In the following description, the same elements as those of thephosphor-containing film 1 shown in FIG. 1 are denoted by the samereference numerals, and a detailed description thereof will be omitted.

FIG. 8A is a schematic plan view of another example of thephosphor-containing film, FIG. 8B is a cross-sectional view taken alonga line B-B of FIG. 8A, and FIG. 8C is a cross-sectional view taken alonga line C-C of FIG. 8A.

The phosphor-containing film 3 shown in FIGS. 8A to 8C comprises, as afluorescent region, a first fluorescent region 35 a in which the firstphosphors 31 a are dispersed in the binder 33 and a second fluorescentregion 35 b in which the second phosphors 31 b different from the firstphosphors 31 a are dispersed in the binder 33. The first fluorescentregion 35 a and the second fluorescent region 35 b are alternatelydisposed in plan view and are dispersedly arranged at differentpositions in the film thickness direction. The first fluorescent region35 a is disposed on the main surface side adjacent to the secondsubstrate film 20 and the second fluorescent region 35 b is disposed onthe main surface side adjacent to the first substrate film 10, and thefirst fluorescent region 35 a and the second fluorescent region 35 b aredisposed so as not to overlap each other in plan view.

The first phosphor 31 a and the second phosphor 31 b are, for example,phosphors having luminescence center wavelengths different from eachother. For example, a phosphor having a luminescence center wavelengthin a wavelength range of 600 to 680 nm is used as the first phosphor 31a, and a phosphor having a luminescence center wavelength in awavelength range of 520 to 560 nm is used as the second phosphor 31 b,and so on.

Although the binder 33 of the first fluorescent region 35 a and thesecond fluorescent region 35 b is made of the same composition in thepresent example, it may be made of a different composition.

FIG. 9A is a plan view schematically showing another example of thephosphor-containing film according to the embodiment of the presentinvention, and FIG. 9B is a cross-sectional view taken along a line B-Bof FIG. 9A.

The phosphor-containing film 4 shown in FIGS. 9A and 9B is differentfrom the phosphor-containing film 3 shown in FIGS. 8A to 8C in that thefirst fluorescent region 35 a and the second fluorescent region 35 bdisposed at different positions in the film thickness directionpartially overlap each other in the case where the film surface isviewed in plan view. In this manner, the first fluorescent region 35 aand the second fluorescent region 35 b disposed at different positionsin the film direction may overlap each other in plan view.

FIG. 10A is a plan view schematically showing another example of thephosphor-containing film according to the embodiment of the presentinvention, and FIG. 10B is a cross-sectional view taken along a line B-Bof FIG. 10A.

The phosphor-containing film 6 shown in FIGS. 10A and 10B comprises astep-like fluorescent region 35 in which quadrangular prism-shapedregions are laminated with a shift of a half cycle. In the fluorescentregion 35, the first phosphors 31 a and the second phosphors 31 b aredispersed in the binder 33. In the present example, the second phosphors31 b are dispersed in the lower step portion of the step-likefluorescent region 35 and the first phosphors 31 a are dispersed in theupper step portion of the step-like fluorescent region 35, but the firstphosphors 31 a and the second phosphors 31 b may be mixed in the entireupper and lower step portions in the fluorescent region 35.

As described above, in the phosphor-containing film according to theembodiment of the present invention, the shape of the fluorescent region35 and the arrangement pattern thereof are not particularly limited. Thefluorescent regions 35 are discretely arranged on the film surface inany case, so that the phosphor 31 in the fluorescent region 35 at thecut end portion deteriorates but the fluorescent region 35 in theportion other than the cut end portion is sealed by being surroundedwith an oxygen-impermeable resin layer 38 in the direction along thefilm surface. Consequently, it is possible to suppress deterioration inperformance due to the penetration of oxygen from the direction alongthe film surface.

Hereinafter, individual constituent elements of the phosphor-containingfilm according to the embodiment of the present invention will bedescribed.

The phosphor-containing film 1 takes a configuration in which thephosphor-containing layer 30 is laminated on one film surface of thefirst substrate film 10, the second substrate film 20 is laminated onthe phosphor-containing layer 30, and the phosphor-containing layer 30is sandwiched between two substrate films 10 and 20.

—Phosphor-Containing Layer—

The phosphor-containing layer 30 comprises a fluorescent region 35containing a plurality of phosphors 31 and a resin layer 38 impermeableto oxygen and filled between the fluorescent regions 35.

<<Region Containing Phosphors (Fluorescent Region)>>

The fluorescent region 35 is constituted of phosphors 31 and a binder 33in which the phosphors 31 are dispersed and is formed by applying andcuring a coating liquid for forming a fluorescent region containing thephosphors 31 and a curable composition to be the binder 33.

<Phosphor>

Various known phosphors can be used as a phosphor which deteriorates bybeing reacted with oxygen upon exposure to oxygen. Examples of thephosphor include inorganic phosphors such as rare earth doped garnet,silicates, aluminates, phosphates, ceramic phosphors, sulfide phosphors,and nitride phosphors, and organic fluorescent substances includingorganic fluorescent dyes and organic fluorescent pigments. In addition,phosphors with rare earth-doped semiconductor fine particles, andsemiconductor nanoparticles (quantum dots and quantum rods) are alsopreferably used. A single kind of phosphor may be used alone, but aplurality of phosphors having different wavelengths may be mixed andused so as to obtain a desired fluorescence spectrum, or a combinationof phosphors of different material constitutions (for example, acombination of a rare earth doped garnet and quantum dots) may be used.

As used herein, the phrase “exposure to oxygen” means exposure to anenvironment containing oxygen, such as in the atmosphere, and the phrase“deteriorates by being reacted with oxygen” means that the phosphor isoxidized so that the performance of the phosphor deteriorates(decreases). The phrase “deteriorate by reacting with oxygen” refers tomainly the luminescence performance declining as compared with thatbefore the reaction with oxygen, but in the case where the phosphor isused as a photoelectric conversion element, means that the photoelectricconversion efficiency declines as compared with that before the reactionwith oxygen.

In the following description, as a phosphor deteriorating by oxygen,mainly quantum dots will be described as an example. However, thephosphor of the present invention is not limited to quantum dots and isnot particularly limited as long as it is a fluorescent coloring agentthat deteriorates due to oxygen, or a material that converts energy fromthe outside into light or converts light into electricity, such as aphotoelectric conversion material.

(Quantum Dot)

The quantum dot is a fine particle of a compound semiconductor having asize of several nm to several tens of nm and is at least excited byincident excitation light to emit fluorescence.

The phosphor of the present embodiment may include at least one quantumdot or may include two or more quantum dots having differentluminescence properties. Known quantum dots include a quantum dot (A)having a luminescence center wavelength in a wavelength range of 600 to680 nm, a quantum dot (B) having a luminescence center wavelength in awavelength range of 500 nm or more to less than 600 nm, and a quantumdot (C) having a luminescence center wavelength in a wavelength range of400 nm or more to less than 500 nm. The quantum dot (A) is excited byexcitation light to emit red light, the quantum dot (B) is excited byexcitation light to emit green light, and the quantum dot (C) is excitedby excitation light to emit blue light.

For example, in the case where blue light is incident as excitationlight to a phosphor-containing layer containing the quantum dot (A) andthe quantum dot (B), red light emitted from the quantum dot (A), greenlight emitted from the quantum dot (B) and blue light penetratingthrough the phosphor-containing layer can realize white light.Alternatively, ultraviolet light can be incident as excitation light toa phosphor-containing layer containing the quantum dots (A), (B), and(C), thereby allowing red light emitted from the quantum dot (A), greenlight emitted from the quantum dot (B), and blue light emitted from thequantum dot (C) to realize white light.

With respect to the quantum dot, reference can be made to, for example,paragraphs [0060] to [0066] of JP2012-169271A, but the quantum dot isnot limited to those described therein. As the quantum dot, commerciallyavailable products can be used without any limitation. The luminescencewavelength of the quantum dot can usually be adjusted by the compositionand size of the particles.

The quantum dot can be added in an amount of, for example, about 0.1 to10 parts by mass with respect to 100 parts by mass of the total amountof the coating liquid.

The quantum dots may be added into the coating liquid in the form ofparticles or in the form of a dispersion liquid in which the quantumdots are dispersed in an organic solvent. It is preferable that thequantum dots be added in the form of a dispersion liquid, from theviewpoint of suppressing aggregation of quantum dot particles. Theorganic solvent used for dispersing the quantum dots is not particularlylimited.

As the quantum dots, for example, core-shell type semiconductornanoparticles are preferable from the viewpoint of improving durability.As the core, Group II-VI semiconductor nanoparticles, Group III-Vsemiconductor nanoparticles, multi-component semiconductornanoparticles, and the like can be used. Specific examples thereofinclude, but are not limited to, CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, InP,InAs, and InGaP. Among them, CdSe, CdTe, InP, InGaP are preferable fromthe viewpoint of emitting visible light with high efficiency. As theshell, CdS, ZnS, ZnO, GaAs, and complexes thereof can be used, but it isnot limited thereto. The luminescence wavelength of the quantum dot canusually be adjusted by the composition and size of the particles.

The quantum dot may be a spherical particle or may be a rod-likeparticle also called a quantum rod, or may be a tetrapod-type particle.A spherical quantum dot or rod-like quantum dot (that is, a quantum rod)is preferable from the viewpoint of narrowing a full width at halfmaximum (FWHM) and enlarging the color reproduction range of a liquidcrystal display.

A ligand having a Lewis basic coordinating group may be coordinated onthe surface of the quantum dot. It is also possible to use quantum dotsin which such a ligand is already coordinated. Examples of the Lewisbasic coordinating group include an amino group, a carboxy group, amercapto group, a phosphine group, and a phosphine oxide group. Specificexamples thereof include hexylamine, decylamine, hexadecylamine,octadecylamine, oleylamine, myristylamine, laurylamine, oleic acid,mercaptopropionic acid, trioctylphosphine, and trioctylphosphine oxide.Among these, hexadecylamine, trioctylphosphine, and trioctylphosphineoxide are preferable, and trioctylphosphine oxide is particularlypreferable.

Quantum dots in which these ligands are coordinated can be produced by aknown synthesis method. For example, such quantum dots can besynthesized by the method described in C. B. Murray, D. J. Norris, M. G.Bawendi, Journal American Chemical Society, 1993, 115(19), pp. 8706 to8715, or The Journal Physical Chemistry, 101, pp. 9463 to 9475, 1997. Inaddition, commercially available quantum dots in which the ligands arecoordinated can be used without any limitation. For example, Lumidot(manufactured by Sigma-Aldrich Co. LLC.) can be mentioned.

In the present invention, the content of the ligand-coordinated quantumdots is preferably 0.01% to 10% by mass and more preferably 0.05% to 5%by mass with respect to the total mass of the polymerizable compoundcontained in the quantum dot-containing composition to be thefluorescent region. It is desirable to adjust the concentration,depending on the thickness of the phosphor-containing film.

The quantum dots may be added to the quantum dot-containing compositionin the form of particles or in the form of a dispersion liquid dispersedin a solvent. It is preferable to add the quantum dots in the form of adispersion liquid from the viewpoint of suppressing aggregation ofparticles of quantum dots. The solvent used here is not particularlylimited.

(Method for Synthesizing Ligand)

The ligand in the quantum dot-containing composition can be synthesizedby a known synthesis method. For example, the ligand can be synthesizedby the method described in JP2007-277514A.

<Curable Composition for Forming Binder of Fluorescent Region>

In the present invention, the curable composition forming a binder ofthe fluorescent region contains a polymer dispersant. Further, thecurable composition preferably contains a polymerizable compound.

(Polymerizable Compound)

The polymerizable compound is preferably an acrylic compound. Amonofunctional or polyfunctional (meth)acrylate monomer is preferable,and a prepolymer or polymer of a monomer may be used as long as it haspolymerizability. In the present specification, the term“(meth)acrylate” refers to one or both of acrylate and methacrylate. Thesame applies to the term “(meth)acryloyl” or the like.

—Monofunctional Ones—

A monofunctional (meth)acrylate monomer may be, for example, acrylicacid or methacrylic acid, or derivatives thereof, more specifically, amonomer having one polymerizable unsaturated bond ((meth)acryloyl group)of (meth)acrylic acid in the molecule. Specific examples thereof includethe following compounds, but the present embodiment is not limitedthereto.

Examples thereof include alkyl (meth)acrylates having 1 to 30 carbonatoms in the alkyl group, such as methyl (meth)acrylate, n-butyl(meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate,isononyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate,and stearyl (meth)acrylate; aralkyl (meth)acrylates having 7 to 20carbon atoms in the aralkyl group, such as benzyl (meth)acrylate;alkoxyalkyl (meth)acrylates having 2 to 30 carbon atoms in thealkoxyalkyl group, such as butoxyethyl (meth)acrylate; aminoalkyl(meth)acrylates having 1 to 20 carbon atoms in total in the (monoalkylor dialkyl)aminoalkyl group, such as N,N-dimethylaminoethyl(meth)acrylate; polyalkylene glycol alkyl ether (meth)acrylates having 1to 10 carbon atoms in the alkylene chain and having 1 to 10 carbon atomsin the terminal alkyl ether, such as diethylene glycol ethyl ether(meth)acrylate, triethylene glycol butyl ether (meth)acrylate,tetraethylene glycol monomethyl ether (meth)acrylate, hexaethyleneglycol monomethyl ether (meth)acrylate, octaethylene glycol monomethylether (meth)acrylate, nonaethylene glycol monomethyl ether(meth)acrylate, dipropylene glycol monomethyl ether (meth)acrylate,heptapropylene glycol monomethyl ether (meth)acrylate, and tetraethyleneglycol monoethyl ether (meth)acrylate; polyalkylene glycol aryl ether(meth)acrylates having 1 to 30 carbon atoms in the alkylene chain andhaving 6 to 20 carbon atoms in the terminal aryl ether, such ashexaethylene glycol phenyl ether (meth)acrylate; (meth)acrylates havingan alicyclic structure and having 4 to 30 carbon atoms in total, such ascyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl(meth)acrylate, and methylene oxide addition cyclodecatriene(meth)acrylate; fluorinated alkyl (meth)acrylates having 4 to 30 carbonatoms in total, such as heptadecafluorodecyl (meth)acrylate;(meth)acrylates having a hydroxyl group, such as 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethyleneglycol mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate,octapropylene glycol mono(meth)acrylate, and glycerol mono ordi(meth)acrylate; (meth)acrylates having a glycidyl group, such asglycidyl (meth)acrylate; polyethylene glycol mono(meth)acrylates having1 to 30 carbon atoms in the alkylene chain, such as tetraethylene glycolmono(meth)acrylate, hexaethylene glycol mono(meth)acrylate, andoctapropylene glycol mono(meth)acrylate; and (meth)acrylamides such as(meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-isopropyl(meth)acrylamide, 2-hydroxyethyl (meth)acrylamide, andacryloylmorpholine.

The amount of the monofunctional (meth)acrylate monomer to be used ispreferably 10 parts by mass or more and more preferably 10 to 80 partsby mass with respect to 100 parts by mass of the total amount of thecurable compound contained in the coating liquid, from the viewpoint ofadjusting the viscosity of the coating liquid to a preferable range.

—Difunctional Ones—

The polymerizable monomer having two polymerizable groups may be, forexample, a difunctional polymerizable unsaturated monomer having twoethylenically unsaturated bond-containing groups. The difunctionalpolymerizable unsaturated monomer is suitable for allowing a compositionto have a low viscosity. In the present embodiment, preferred is a(meth)acrylate-based compound which is excellent in reactivity and whichhas no problems associated with a remaining catalyst and the like.

In particular, neopentyl glycol di(meth)acrylate, 1,9-nonanedioldi(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropyleneglycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate,hydroxypivalate neopentyl glycol di(meth)acrylate, polyethylene glycoldi(meth)acrylate, dicyclopentenyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, dicyclopentanyl di(meth)acrylate, or the like issuitably used in the present invention.

The amount of the difunctional (meth)acrylate monomer to be used ispreferably 5 parts by mass or more and more preferably 10 to 80 parts bymass with respect to 100 parts by mass of the total amount of thecurable compound contained in the coating liquid, from the viewpoint ofadjusting the viscosity of the coating liquid to a preferable range.

—Tri- or Higher Functional Ones—

The polymerizable monomer having three or more polymerizable groups maybe, for example, a polyfunctional polymerizable unsaturated monomerhaving three or more ethylenically unsaturated bond-containing groups.Such a polyfunctional polymerizable unsaturated monomer is excellent interms of imparting mechanical strength. In the present embodiment,preferred is a (meth)acrylate-based compound which is excellent inreactivity and which has no problems associated with a remainingcatalyst and the like.

Specifically, epichlorohydrin (ECH)-modified glycerol tri(meth)acrylate,ethylene oxide (EO)-modified glycerol tri(meth)acrylate, propylene oxide(PO)-modified glycerol tri(meth)acrylate, pentaerythritol triacrylate,pentaerythritol tetraacrylate, EO-modified phosphoric acid triacrylate,trimethylolpropane tri(meth)acrylate, caprolactone-modifiedtrimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropanetri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate,tris(acryloxyethyl)isocyanurate, dipentaerythritol hexa(meth)acrylate,dipentaerythritol penta(meth)acrylate, caprolactone-modifieddipentaerythritol hexa(meth)acrylate, dipentaerythritolhydroxypenta(meth)acrylate, alkyl-modified dipentaerythritolpenta(meth)acrylate, dipentaerythritol poly(meth)acrylate,alkyl-modified dipentaerythritol tri(meth)acrylate, ditrimethylolpropanetetra(meth)acrylate, pentaerythritolethoxy tetra(meth)acrylate,pentaerythritol tetra(meth)acrylate, or the like is suitable.

Among them, EO-modified glycerol tri(meth)acrylate, PO-modified glyceroltri(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modifiedtrimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropanetri(meth)acrylate, dipentaerythritol hexa(meth)acrylate,dipentaerythritol penta(meth)acrylate, pentaerythritolethoxytetra(meth)acrylate, or pentaerythritol tetra(meth)acrylate is suitablyused in the present invention.

The amount of the polyfunctional (meth)acrylate monomer to be used ispreferably 5 parts by mass or more from the viewpoint of the coatingfilm hardness of the phosphor-containing layer after curing, andpreferably 95 parts by mass or less from the viewpoint of suppressinggelation of the coating liquid, with respect to 100 parts by mass of thetotal amount of the curable compound contained in the coating liquid.

From the viewpoint of further improving the heat resistance of thefluorescent region (binder), the (meth)acrylate monomer is preferably analicyclic acrylate. Examples of such a monofunctional (meth)acrylatemonomer include dicyclopentenyl (meth)acrylate, dicyclopentanyl(meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate. Examples ofthe difunctional (meth)acrylate monomer include tricyclodecanedimethanoldi(meth)acrylate.

The total amount of the polymerizable compound in the curablecomposition forming a binder is preferably 70 to 99 parts by mass andmore preferably 85 to 97 parts by mass with respect to 100 parts by massof the curable composition, from the viewpoint of handleability andcurability of the composition. —Epoxy-Based Compounds—

The polymerizable monomer may be, for example, a compound having acyclic group such as a ring-opening polymerizable cyclic ether groupsuch as an epoxy group or an oxetanyl group. Such a compound may be morepreferably, for example, a compound having a compound (epoxy compound)having an epoxy group. Use of the compound having an epoxy group or anoxetanyl group in combination with the (meth)acrylate-based compoundtends to improve adhesiveness to the barrier layer.

Examples of the compound having an epoxy group include polyglycidylesters of polybasic acids, polyglycidyl ethers of polyhydric alcohols,polyglycidyl ethers of polyoxyalkylene glycols, polyglycidyl esters ofaromatic polyols, hydrogenated compounds of polyglycidyl ethers ofaromatic polyols, urethane polyepoxy compounds, and epoxidizedpolybutadienes. These compounds may be used alone or in combination oftwo or more thereof.

Examples of other compounds having an epoxy group, which may bepreferably used, include aliphatic cyclic epoxy compounds, bisphenol Adiglycidyl ethers, bisphenol F diglycidyl ethers, bisphenol S diglycidylethers, brominated bisphenol A diglycidyl ethers, brominated bisphenol Fdiglycidyl ethers, brominated bisphenol S diglycidyl ethers,hydrogenated bisphenol A diglycidyl ethers, hydrogenated bisphenol Fdiglycidyl ethers, hydrogenated bisphenol S diglycidyl ethers,1,4-butanediol diglycidyl ethers, 1,6-hexanediol diglycidyl ethers,glycerin triglycidyl ethers, trimethylolpropane triglycidyl ethers,polyethylene glycol diglycidyl ethers, and polypropylene glycoldiglycidyl ethers; polyglycidyl ethers of polyether polyols, obtained byadding one or two or more alkylene oxides to an aliphatic polyhydricalcohol such as ethylene glycol, propylene glycol, or glycerin;diglycidyl esters of aliphatic long chain dibasic acids; monoglycidylethers of aliphatic higher alcohols; monoglycidyl ethers such aspolyether alcohols, obtained by adding an alkylene oxide to phenol,cresol, butyl phenol, or these compounds; and glycidyl esters of higherfatty acids.

Among these components, aliphatic cyclic epoxy compounds, bisphenol Adiglycidyl ethers, bisphenol F diglycidyl ethers, hydrogenated bisphenolA diglycidyl ethers, hydrogenated bisphenol F diglycidyl ethers,1,4-butanediol diglycidyl ethers, 1,6-hexanediol diglycidyl ethers,glycerin triglycidyl ethers, trimethylolpropane triglycidyl ethers,neopentyl glycol diglycidyl ethers, polyethylene glycol diglycidylethers, polypropylene glycol diglycidyl ethers, and the like arepreferable.

Examples of commercially available products which can be suitably usedas the compound having an epoxy group or an oxetanyl group includeUVR-6216 (manufactured by Union Carbide Corporation), glycidol, AOEX24,CYCLOMER A200, CELLOXIDE 2021P and CELLOXIDE 8000 (all manufactured byDaicel Corporation), 4-vinylcyclohexene dioxide (manufactured by SigmaAldrich, Inc.), EPIKOTE 828, EPIKOTE 812, EPIKOTE 1031, EPIKOTE 872 andEPIKOTE CT508 (all manufactured by Yuka Shell Epoxy K.K.), and KRM-2400,KRM-2410, KRM-2408, KRM-2490, KRM-2720 and KRM-2750 (all manufactured byAsahi Denka Kogyo K.K.). These compounds may be used alone or incombination of two or more thereof.

Although there are no particular restrictions on the production methodof such a compound having an epoxy group or an oxetanyl group, thecompound can be synthesized with reference to, for example, Literaturessuch as Fourth Edition Experimental Chemistry Course 20 OrganicSynthesis II, p. 213˜, 1992, published by Maruzen KK; Ed. by AlfredHasfner, The chemistry of heterocyclic compounds-Small Ring Heterocyclespart 3 Oxiranes, John & Wiley and Sons, An Interscience Publication, NewYork, 1985, Yoshimura, Adhesion, Vol. 29, No. 12, 32, 1985, Yoshimura,Adhesion, Vol. 30, No. 5, 42, 1986, Yoshimura, Adhesion, Vol. 30, No. 7,42, 1986, JP1999-100378A (JP-H11-100378A), JP2906245B, and JP2926262B.

A vinyl ether compound may be used as the curable compound.

As the vinyl ether compound, a known vinyl ether compound can beappropriately selected, and, for example, the compound described inparagraph [0057] of JP2009-073078A may be preferably adopted.

Such a vinyl ether compound can be synthesized by, for example, themethod described in Stephen. C. Lapin, Polymers Paint Colour Journal.179 (4237), 321 (1988), namely, by a reaction of a polyhydric alcohol ora polyhydric phenol with acetylene, or a reaction of a polyhydricalcohol or a polyhydric phenol with a halogenated alkyl vinyl ether. Thevinyl ether compound may be used alone or in combination of two or morethereof.

For the coating liquid, a silsesquioxane compound having a reactivegroup described in JP2009-073078A can also be used from the viewpoint ofa decrease in viscosity and an increase in hardness.

As the curable compound for the resin layer 38 having impermeability tooxygen, those capable of forming a resin layer having high gas barrierproperties such as a (meth)acrylate compounds, an epoxy-based compound,and the like are particularly preferable.

Among the foregoing curable compounds, a (meth)acrylate compound ispreferable from the viewpoint of composition viscosity andphotocurability, and acrylate is more preferable. In the presentinvention, a polyfunctional polymerizable compound having two or morepolymerizable functional groups is preferable. In the present invention,particularly, the compounding ratio of the monofunctional (meth)acrylatecompound to the polyfunctional (meth)acrylate compound is preferably80/20 to 0/100, more preferably 70/30 to 0/100, and still morepreferably 40/60 to 0/100 in terms of mass ratio. By selecting anappropriate ratio, it is possible to provide sufficient curability andmake the composition low in viscosity.

The ratio of the difunctional (meth)acrylate to the tri- or higherfunctional (meth)acrylate in the polyfunctional (meth)acrylate compoundis preferably 100/0 to 20/80, more preferably 100/0 to 50/50, and stillmore preferably 100/0 to 70/30 in terms of mass ratio. Since the tri- orhigher functional (meth)acrylate has a higher viscosity than thedifunctional (meth)acrylate, a larger amount of the difunctional(meth)acrylate is preferable because the viscosity of the curablecompound for a resin layer having impermeability to oxygen in thepresent invention can be lowered.

From the viewpoint of enhancing the impermeability to oxygen, it ispreferable to include a compound containing a substituent having anaromatic structure and/or an alicyclic hydrocarbon structure as thepolymerizable compound. The polymerizable compound having an aromaticstructure and/or an alicyclic hydrocarbon structure is more preferablycontained in an amount of 50% by mass or more and still more preferably80% by mass or more.

The polymerizable compound having an aromatic structure is preferably a(meth)acrylate compound having an aromatic structure. As the(meth)acrylate compound having an aromatic structure, a monofunctional(meth)acrylate compound having a naphthalene structure, such as 1- or2-naphthyl (meth)acrylate, 1- or 2-naphthylmethyl (meth)acrylate, or 1-or 2-naphthylethyl (meth)acrylate, a monofunctional acrylate having asubstituent on the aromatic ring, such as benzyl acrylate, and adifunctional acrylate such as catechol diacrylate or xylylene glycoldiacrylate are particularly preferable.

As the polymerizable compound having an alicyclic hydrocarbon structure,isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate,dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate,adamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate,tetracyclododecanyl (meth)acrylate, and the like are preferable.

In addition, in the case where (meth)acrylate is used as thepolymerizable compound, acrylate is preferable to methacrylate from theviewpoint of excellent curability.

<Polymerization Initiator>

The coating liquid may contain a known polymerization initiator as apolymerization initiator. With respect to the polymerization initiator,for example, reference can be made to paragraph [0037] ofJP2013-043382A. The polymerization initiator is preferably in an amountof 0.1% by mol or more and more preferably 0.5% to 2% by mol based onthe total amount of the curable compound contained in the coatingliquid. In addition, the polymerization initiator is preferablycontained in an amount of 0.1% by mass to 10% by mass and morepreferably 0.2% by mass to 8% by mass, as the percentage by mass in thetotal curable composition excluding the volatile organic solvent.

—Photopolymerization Initiator—

The curable compound preferably contains a photopolymerizationinitiator. Any photopolymerization initiator may be used as long as itis a compound capable of generating an active species that polymerizesthe polymerizable compound upon irradiation with light. Examples of thephotopolymerization initiator include a cationic polymerizationinitiator and a radical polymerization initiator, among which a radicalpolymerization initiator is preferable. Further, in the presentinvention, a plurality of photopolymerization initiators may be used incombination.

The content of the photopolymerization initiator is, for example, 0.01%to 15% by mass, preferably 0.1% to 12% by mass, and more preferably 0.2%to 7% by mass, in the total composition excluding the solvent. In thecase where two or more photopolymerization initiators are used, thetotal content thereof falls within the above range.

In the case where the content of the photopolymerization initiator is0.01% by mass or more, sensitivity (fast curability) and coating filmhardness tend to improve, which is preferable. On the other hand, in thecase where the content of the photopolymerization initiator is 15% bymass or less, light transmittance, colorability, handleability, and thelike tend to improve, which is preferable.

In a system including a dye and/or a pigment, they may act as a radicaltrapping agent and affect photopolymerizability and sensitivity. Inconsideration of this point, in these applications, the addition amountof the photopolymerization initiator is optimized. On the other hand, inthe composition used in the present invention, the dye and/or pigment isnot an essential component, and the optimum range of thephotopolymerization initiator may be different from that in the field ofa curable composition for liquid crystal display color filter, or thelike.

As the radical photopolymerization initiator, for example, acommercially available initiator can be used. The examples thereofinclude those described, for example, in paragraph [0091] ofJP2008-105414A, which are preferably used. Among them, anacetophenone-based compound, an acylphosphine oxide-based compound, andan oxime ester-based compound are preferable from the viewpoint ofcuring sensitivity and absorption properties.

The acetophenone-based compound may be preferably, for example, ahydroxyacetophenone-based compound, a dialkoxyacetophenone-basedcompound, and an aminoacetophenone-based compound.

The hydroxyacetophenone-based compound may be preferably, for example,Irgacure (registered trademark) 2959(1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one,Irgacure (registered trademark) 184 (1-hydroxycyclohexyl phenylketone),Irgacure (registered trademark) 500 (1-hydroxycyclohexyl phenylketone,benzophenone), and Darocur (registered trademark) 1173(2-hydroxy-2-methyl-1-phenyl-1-propan-1-one), all of which arecommercially available from BASF Corporation.

The dialkoxyacetophenone-based compound may be preferably, for example,Irgacure (registered trademark) 651(2,2-dimethoxy-1,2-diphenylethan-1-one) which is commercially availablefrom BASF Corporation.

The aminoacetophenone-based compound may be preferably, for example,Irgacure (registered trademark) 369(2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1), Irgacure(registered trademark) 379 (EG)(2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)butan-1-one, and Irgacure (registered trademark) 907(2-methyl-1-[4-methylthiophenyl]-2-morpholinopropan-1-one), all of whichare commercially available from BASF Corporation.

The acylphosphine oxide-based compound may be preferably, for example,Irgacure (registered trademark) 819(bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide), and Irgacure(registered trademark) 1800(bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide), allof which are commercially available from BASF Corporation, and LucirinTPO (2,4,6-trimethylbenzoyldiphenylphosphine oxide) and Lucirin TPO-L(2,4,6-trimethylbenzoylphenylethoxyphosphine oxide), both of which arecommercially available from BASF Corporation.

The oxime ester-based compound may be preferably, for example, Irgacure(registered trademark) OXE01 (1,2-octanedione,1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime)), Irgacure (registeredtrademark) OXE02 (ethanone,1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, and1-(O-acetyloxime)), all of which are commercially available from BASFCorporation.

The cationic photopolymerization initiator is preferably a sulfoniumsalt compound, an iodonium salt compound, an oxime sulfonate compound,or the like, and examples thereof include4-methylphenyl-4-(1-methylethyl)phenyliodoniumtetrakis(pentafluorophenyl)borate (PI 2074 manufactured by Rhodia),4-methylphenyl-4-(2-methylpropyl)phenyliodonium hexafluorophosphate(IRGACURE 250 manufactured by BASF Corporation), and IRGACURE PAG103,108, 121, and 203 (all manufactured by BASF Corporation).

The photopolymerization initiator needs to be selected appropriatelywith respect to the wavelength of the light source to be used, but it ispreferable that the photopolymerization initiator does not generate gasduring mold pressurization/exposure.

In the case where gas is generated, the mold is contaminated, so it isnecessary to frequently clean the mold, or the photocurable compositionis deformed in the mold, which contributes to problems such asdeterioration of transfer pattern accuracy.

The curable compound for the resin layer 38 having impermeability tooxygen is preferably a radical polymerization curable composition inwhich the polymerizable compound is a radically polymerizable compoundand the photopolymerization initiator is a radical polymerizationinitiator that generates radicals by light irradiation.

(Polymer)

The curable composition forming a binder may contain a polymer.

Examples of the polymer include poly(meth)acrylate,poly(meth)acrylamide, polyester, polyurethane, polyurea, polyamide,polyether, and polystyrene.

(Other Additives)

The coating liquid for forming a fluorescent region may contain aviscosity adjuster, a silane coupling agent, a surfactant, anantioxidant, an oxygen getter, a polymerization inhibitor, an inorganicparticle, and the like.

—Viscosity Adjuster—

The coating liquid for forming a fluorescent region may contain aviscosity adjuster, if necessary. Addition of a viscosity adjuster makesit possible to adjust to the desired viscosity. The viscosity adjusteris preferably a filler having a particle diameter of 5 to 300 nm. Inaddition, the viscosity adjuster may be a thixotropic agent.

In the present invention and the present specification, the term“thixotropy” refers to a property of decreasing the viscosity withincreasing shear rate in a liquid composition, and the term “thixotropicagent” refers to a material having a function of imparting thixotropy toa composition by incorporation thereof into a liquid composition.

Specific examples of the thixotropic agent include fumed silica,alumina, silicon nitride, titanium dioxide, calcium carbonate, zincoxide, talc, mica, feldspar, kaolinite (kaolin clay), pyrophyllite(pyrophyllite clay), sericite (silk mica), bentonite,smectite-vermiculites (montmorillonite, beidellite, nontronite,saponite, and the like), organic bentonite, and organic smectite.

—Silane Coupling Agent—

The phosphor-containing layer (fluorescent region) formed from thecoating liquid containing a silane coupling agent can exhibit excellentdurability due to having strong adhesiveness to an adjacent layer due tothe silane coupling agent.

In addition, the phosphor-containing layer formed from the coatingliquid containing a silane coupling agent is also preferable in formingthe relationship of “adhesion force A between support film and barrierlayer<adhesion force B between phosphor-containing layer and barrierlayer,” which is a preferable adhesion force condition. This is mainlydue to the fact that the silane coupling agent contained in thephosphor-containing layer forms a covalent bond with the surface of theadjacent layer or the constituent component of the phosphor-containinglayer by hydrolysis reaction or condensation reaction. In the case wherethe silane coupling agent has a reactive functional group such as aradical polymerizable group, the formation of a crosslinking structurewith a monomer component constituting the phosphor-containing layer canalso contribute to an improvement in adhesiveness to the layer adjacentto the phosphor-containing layer.

For the silane coupling agent, a known silane coupling agent can be usedwithout any limitation. From the viewpoint of adhesiveness, a preferredsilane coupling agent may be, for example, a silane coupling agentrepresented by General Formula (1) described in JP2013-043382A.

(In General Formula (1), R₁ to R₆ are each independently a substitutedor unsubstituted alkyl group or aryl group, provided that at least oneof R₁, . . . , or R₆ is a substituent containing a radical polymerizablecarbon-carbon double bond.)

R₁ to R₆ are preferably an unsubstituted alkyl group or an unsubstitutedaryl group, except for a case where R₁ to R₆ are a substituentcontaining a radical polymerizable carbon-carbon double bond. The alkylgroup is preferably an alkyl group having 1 to 6 carbon atoms and morepreferably a methyl group. The aryl group is preferably a phenyl group.R₁ to R₆ are each particularly preferably a methyl group.

It is preferable that at least one of R₁, . . . , or R₆ has asubstituent containing a radical polymerizable carbon-carbon doublebond, and two of R₁ to R₆ are a substituent containing a radicalpolymerizable carbon-carbon double bond. Further, it is particularlypreferable that among R₁ to R₃, the number of those having a substituentcontaining a radical polymerizable carbon-carbon double bond is 1, andamong R₄ to R₆, the number of those having a substituent containing aradical polymerizable carbon-carbon double bond is 1.

In the case where the silane coupling agent represented by GeneralFormula (1) has two or more substituents containing a radicalpolymerizable carbon-carbon double bond, the respective substituents maybe the same or different, and are preferably the same.

It is preferable that the substituent containing a radical polymerizablecarbon-carbon double bond is represented by —X—Y where X is a singlebond, an alkylene group having 1 to 6 carbon atoms, or an arylene group,preferably a single bond, a methylene group, an ethylene group, apropylene group, or a phenylene group; and Y is a radical polymerizablecarbon-carbon double bond group, preferably an acryloyloxy group, amethacryloyloxy group, an acryloylamino group, a methacryloylaminogroup, a vinyl group, a propenyl group, a vinyloxy group, or avinylsulfonyl group, and more preferably a (meth)acryloyloxy group.

R₁ to R₆ may also have a substituent other than the substituentcontaining a radical polymerizable carbon-carbon double bond. Examplesof such a substituent include alkyl groups (for example, a methyl group,an ethyl group, an isopropyl group, a tert-butyl group, a n-octyl group,an n-decyl group, an n-hexadecyl group, a cyclopropyl group, acyclopentyl group, and a cyclohexyl group), aryl groups (for example, aphenyl group and a naphthyl group), halogen atoms (for example,fluorine, chlorine, bromine, and iodine), acyl groups (for example, anacetyl group, a benzoyl group, a formyl group, and a pivaloyl group),acyloxy groups (for example, an acetoxy group, an acryloyloxy group, anda methacryloyloxy group), alkoxycarbonyl groups (for example, amethoxycarbonyl group and an ethoxycarbonyl group), aryloxycarbonylgroups (for example, a phenyloxycarbonyl group), and sulfonyl groups(for example, a methanesulfonyl group and a benzenesulfonyl group).

The silane coupling agent is contained in the coating liquid in therange of preferably 1% to 30% by mass, more preferably 3% to 30% bymass, and still more preferably 5% to 25% by mass, from the viewpoint offurther improving the adhesiveness to the adjacent layer.

—Surfactant—

The coating liquid for forming a fluorescent region may contain at leastone surfactant containing fluorine atoms in an amount of 20% by mass ormore.

The surfactant preferably contains 25% by mass or more of fluorine atomsand more preferably 28% by mass or more of fluorine atoms. The upperlimit value of the fluorine atom content is not specifically defined,but it is, for example, 80% by mass or less and preferably 70% by massor less.

The surfactant used in the present invention is preferably a compoundhaving an alkyl group having a fluorine atom, a cycloalkyl group havinga fluorine atom, or an aryl group having a fluorine atom.

The alkyl group containing a fluorine atom is a linear or branched alkylgroup in which at least one hydrogen atom is substituted with a fluorineatom. The alkyl group preferably has 1 to 10 carbon atoms and morepreferably 1 to 4 carbon atoms. The alkyl group containing a fluorineatom may further have a substituent other than a fluorine atom.

The cycloalkyl group containing a fluorine atom is a monocyclic orpolycyclic cycloalkyl group in which at least one hydrogen atom issubstituted with a fluorine atom. The cycloalkyl group containing afluorine atom may further have a substituent other than a fluorine atom.

The aryl group containing a fluorine atom is an aryl group in which atleast one hydrogen atom is substituted with a fluorine atom. Examples ofthe aryl group include a phenyl group and a naphthyl group. The arylgroup containing a fluorine atom may further have a substituent otherthan a fluorine atom.

By having such a structure, it is considered that the surface unevendistribution ability becomes satisfactory, and partial compatibilitywith the polymer occurs and phase separation is suppressed.

The molecular weight of the surfactant is preferably 300 to 10,000 andmore preferably 500 to 5,000.

The content of the surfactant is, for example, 0.01% to 10% by mass,preferably 0.1% to 7% by mass, and more preferably 0.5% to 4% by mass inthe total composition excluding the solvent. In the case where two ormore surfactants are used, the total content thereof falls within theabove range.

Examples of the surfactant include FLUORAD FC-430 and FC-431 (tradenames, manufactured by Sumitomo 3M Ltd.), SURFLON S-382 (trade name,manufactured by Asahi Glass Co., Ltd.), EFTOP “EF-122A, 122B, 122C,EF-121, EF-126, EF-127, and MF-100” (manufactured by Tohkem ProductsCorporation), PF-636, PF-6320, PF-656 and PF-6520 (trade names, allmanufactured by OMNOVA Solutions, Inc.), FTERGENT FT250, FT251 and DFX18(trade names, all manufactured by NEOS Co., Ltd.), UNIDYNE DS-401,DS-403 and DS-451 (trade names, all manufactured by Daikin IndustriesLtd.), MEGAFACE 171, 172, 173, 178K and 178A (trade names, allmanufactured by DIC Corporation), X-70-090, X-70-091, X-70-092 andX-70-093 (trade names, all manufactured by Shin-Etsu Chemical Co.,Ltd.), and MEGAFACE R-08 and XRB-4 (trade names, all manufactured by DICCorporation).

(Other Components)

In addition to the above-mentioned components, the curable compound maycontain other components such as an antioxidant as long as the effect ofthe present invention is not impaired, depending on various purposes.—Antioxidant—

The curable compound preferably contains a known antioxidant. Theantioxidant is for suppressing color fading by heat orphoto-irradiation, and for suppressing color fading by various oxidizinggases such as ozone, active oxygen NO_(x), and SO_(x) (X is an integer).Especially in the present invention, addition of the antioxidant bringsabout advantages that the cured film is prevented from being colored andthe film thickness is prevented from being reduced throughdecomposition.

Further, two or more antioxidants may be used as the antioxidant.

The content of the antioxidant in the curable compound is preferably0.2% by mass or more, more preferably 1% by mass or more, and still morepreferably 2% by mass or more with respect to the total mass of thecurable compound.

On the other hand, the antioxidant may be altered due to the interactionwith oxygen. The altered antioxidant may induce decomposition of thequantum dot-containing polymerizable composition, resulting in loweringof adhesiveness, brittleness deterioration, and lowering of quantum dotluminous efficiency. From the viewpoint of preventing thesedeteriorations, the content of the antioxidant is preferably 20% by massor less, more preferably 15% by mass or less, and still more preferably10% by mass or less.

The antioxidant is preferably at least one of a radical inhibitor, ametal deactivator, a singlet oxygen scavenger, a superoxide scavenger,and a hydroxy radical scavenger. Examples of the antioxidant include aphenol-based antioxidant, a hindered amine-based antioxidant, aquinone-based antioxidant, a phosphorus-based antioxidant, and athiol-based antioxidant.

Examples of the phenol-based antioxidant include2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, distearyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate,1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acidamide], 4,4′-thiobis(6-tert-butyl-m-cresol),2,2′-methylenebis(4-methyl-6-tert-butylphenol),2,2′-methylenebis(4-ethyl-6-tert-butylphenol),4,4′-butylidenebis(6-tert-butyl-m-cresol),2,2′-ethylidenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(4-sec-butyl-6-tert-butylphenol),1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane,1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl-5-methylbenzyl)phenol,stearyl(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acidmethyl]methane ((ADEKASTAB AO-60, manufactured by ADEKA Corporation)),thiodiethylene glycolbis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,6-hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butyl acid]glycol ester,bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl]terephthalate,1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate,3,9-bis[1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,1 0-tetraoxaspiro[5,5]undecane, and triethylene glycolbis[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate].

Examples of the phosphorus-based antioxidant include trisnonylphenylphosphite,tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite,tridecyl phosphite, octyldiphenyl phosphite, di(decyl)monophenylphosphite, di(tridecyl)pentaerythritol diphosphite,di(nonylphenyl)pentaerythritol diphosphite,bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite,bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite,bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite,bis(2,4-dicumylphenyl)pentaerythritol diphosphite,tetra(tridecyl)isopropylidenediphenol diphosphite,tetra(tridecyl)-4,4′-n-butylidenebis(2-tert-butyl-5-methylphenol)diphosphite,hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butanetriphosphite, tetrakis(2,4-di-tert-butylphenyl)biphenylenediphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide,2,2′-methylene-bis(4,6-tert-butylphenyl)-2-ethylhexyl phosphite,2,2′-methylene-bis(4,6-tert-butylphenyl)-octadecyl phosphite,2,2′-ethylidene-bis(4,6-di-tert-butylphenyl)fluorophosphite,tris(2-[(2,4,8,10-tetrakis-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine,and phosphites of 2-ethyl-2-butylpropylene glycol and2,4,6-tri-tert-butylphenol.

The amount of these phosphorus-based antioxidants added is preferably0.001 to 10 parts by mass and particularly preferably 0.05 to 5 parts bymass, with respect to 100 parts by mass of the polyolefin-based resin.

Examples of the thiol-based antioxidant include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristylthiodipropionate, and distearyl thiodipropionate; and pentaerythritoltetra(β-alkyl mercaptopropionic acid) esters.

The hindered amine-based antioxidant is also referred to as a hinderedamine light stabilizer (HALS), and has a structure in which all hydrogenatoms on carbons at 2- and 6-positions of piperidine are substitutedwith methyl groups, preferably a group represented by Formula 1. InFormula 1, X represents a hydrogen atom or an alkyl group. Among thegroups represented by Formula 1, HALS having a2,2,6,6-tetramethyl-4-piperidyl group in which X is a hydrogen atom, ora 1,2,2,6,6-pentamethyl-4-piperidyl group in which X is a methyl groupis particularly preferably adopted.

A number of HALS having a structure in which a group represented byFormula 1 is bonded to a —COO— group, that is, a group represented byFormula 2 are commercially available, but these can be preferably used.

Specific examples of HALS that can be preferably used in the presentinvention include those represented by the following formulae. Here, the2,2,6,6-tetramethyl-4-piperidyl group is represented by R and the1,2,2,6,6-pentamethyl-4-piperidyl group is represented by R′.

ROC(═O)(CH₂)₈C(═O)OR, ROC(═O)C(CH₃)═CH₂, R′OC(═O)C(CH₃)═CH₂,CH₂(COOR)CH(COOR)CH(COOR)CH₂COOR, CH₂(COOR′)CH(COOR′)CH(COOR′)CH₂COOR′,a compound represented by Formula 3, and the like.

Specific examples of HALS include hindered amine compounds such as2,2,6,6-tetramethyl-4-piperidylstearate,1,2,2,6,6-pentamethyl-4-piperidylstearate,2,2,6,6-tetramethyl-4-piperidylbenzoate,bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate,bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate,bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate,tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate,tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate,bis(2,2,6,6-tetramethyl-4-piperidyl)-di(tridecyl)-1,2,3,4-butanetetracarboxylate,bis(1,2,2,6,6-pentamethyl-4-piperidyl)-di(tridecyl)-1,2,3,4-butanetetracarboxylate,bis(1,2,2,4,4-pentamethyl-4-piperidyl)-2-butyl-2-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate,1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol/diethyl succinatepolycondensate,1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane/2,4-dichloro-6-morpholino-s-triazinepolycondensate,1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hcxane/2,4-dichloro-6-tert-octylamino-s-triazinepolycondensate,1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazin-6-yl]-1,5,8,12-tetraazadodecane,1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazin-6-yl]-1,5,8-12-tetraazadodecane,1,6,11-tris[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazin-6-yl]aminoundecane,and1,6,11-tris[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazin-6-yl]aminoundecane.

Specific products of HALS include, but are not limited to, TINUVIN 123,TINUVIN 144, TINUVIN 765, TINUVIN 770, TINUVIN 622, CHIMASSORB 944, andCHIMAS SORB 119 (all of which are trade names of Ciba SpecialtyChemicals Inc.), ADEKASTAB LA 52, ADEKASTAB LA 57, ADEKASTAB LA 62,ADEKASTAB LA 67, ADEKASTAB LA 82, ADEKASTAB LA 87, and ADEKASTAB LX 335(all of which are trade names of Asahi Denka Kogyo KK).

Among the HALS, those having a relatively small molecular weight arepreferable because of easy diffusion from the resin layer to thefluorescent region. Preferred HALS in this viewpoint are compoundsrepresented by ROC(═O)(CH₂)₈C(═O)OR, R′OC(═O)C(CH₃)═CH₂, and the like.

Among the above-mentioned antioxidants, at least one of a hinderedphenol compound, a hindered amine compound, a quinone compound, ahydroquinone compound, a tocopherol compound, an aspartic acid compound,or a thiol compound is more preferable, and at least one of a citricacid compound, an ascorbic acid compound, or a tocopherol compound isstill more preferable.

Although these compounds are not particularly limited, preferredexamples thereof include hindered phenol, hindered amine, quinone,hydroquinone, tocopherol, aspartic acid, thiol, citric acid, tocopherylacetate, and tocopheryl phosphate per se, and salts or ester compoundsthereof.

One example of the antioxidant is shown below.

Ascorbic acid palmitic acid ester (ascorbyl palmitate)

-   -   Tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate        (trade name: ADEKASTAB LA-52, manufactured by ADEKA Corporation)

1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H, 5H)-trione (trade name: ADEKASTAB AO-20, manufactured by ADEKACorporation)

Tributyl citrate

3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane (trade name: ADEKASTAB PEP-36, manufactured by ADEKACorporation)

Dilauryl thiodipropionate (IRGANOX PS 800, 800FD, manufactured by BASFCorporation)

—Oxygen Getter—

A known substance used as a getter of an organic EL device can be usedas the oxygen getter. The oxygen getter may be either an inorganicgetter or an organic getter, and preferably includes at least onecompound selected from a metal oxide, a metal halide, a metal sulfate, ametal perchlorate, a metal carbonate, a metal alkoxide, a metalcarboxylate, a metal chelate, and a zeolite (aluminosilicate).

Examples of such an inorganic oxygen getter include calcium oxide (CaO),barium oxide (BaO), magnesium oxide (MgO), strontium oxide (SrO),lithium sulfate (Li₂SO₄), sodium sulfate (Na₂SO₄), calcium sulfate(CaSO₄), magnesium sulfate (MgSO₄), cobalt sulfate (CoSO₄), galliumsulfate (Ga₂(SO₄)₃), titanium sulfate (Ti(SO₄)₂), and nickel sulfate(NiSO₄).

The organic getter is not particularly limited as long as it is amaterial that takes in water by a chemical reaction and does not becomeopaque before and after the reaction. Here, the organometallic compoundmeans a compound having a metal-carbon bond, a metal-oxygen bond, ametal-nitrogen bond or the like. In the case where water reacts with theorganometallic compound, the above-mentioned bond of the compound breaksdue to a hydrolysis reaction to result in a metal hydroxide. Dependingon the metal, hydrolytic polycondensation may be carried out to increasethe molecular weight after the reaction into the metal hydroxide.

As the metal of the metal alkoxide, the metal carboxylate, and the metalchelate, it is preferable to use a metal having good reactivity withwater as the organometallic compound, that is, a metal atom which iseasily breakable from a variety of bonds by the action of water.Specific examples thereof include aluminum, silicon, titanium,zirconium, bismuth, strontium, calcium, copper, sodium, and lithium. Inaddition, cesium, magnesium, barium, vanadium, niobium, chromium,tantalum, tungsten, chromium, indium, iron, and the like can bementioned. In particular, a desiccating agent of an organometalliccompound having aluminum as a central metal is preferable in terms ofdispersibility in a resin and reactivity with water. Examples of theorganic group include an unsaturated hydrocarbon such as a methoxygroup, an ethoxy group, a propoxy group, a butoxy group, a 2-ethylhexylgroup, an octyl group, a decyl group, a hexyl group, an octadecyl group,a stearyl group, a saturated hydrocarbon, a branched unsaturatedhydrocarbon, a branched saturated hydrocarbon, an alkoxy group orcarboxyl group containing a cyclic hydrocarbon, and a β-diketonato groupsuch as an acetylacetonate group or a dipivaloylmethanato group.

Among them, aluminum ethyl acetoacetates having 1 to 8 carbon atomsshown in the following chemical formulae are suitably used from theviewpoint that a sealing composition having excellent transparency canbe formed.

(in the formula, R₅ to R₈ each represent an organic group including analkyl group, an aryl group, an alkoxy group, a cycloalkyl group or anacyl group, each of which has 1 to 8 carbon atoms, and M represents atrivalent metal atom. In addition, R₅ to R₈ may be the same organicgroup or different organic group.)

The above-mentioned aluminum ethyl acetoacetates having 1 to 8 carbonatoms are commercially available, for example, from Kawaken FineChemical Co., Ltd. or Hope Pharmaceutical Co., Ltd.

The oxygen getter is in particulate or powder form. The average particlediameter of the oxygen getter may be usually in the range of less than20 μm, preferably 10 μm or less, more preferably 2 μm or less, and stillmore preferably 1 μm or less. From the viewpoint of scattering property,the average particle diameter of the oxygen getter is preferably 0.3 to2 and more preferably 0.5 to 1.0 μm. The term “average particlediameter” as used herein refers to an average value of particlediameters calculated from a particle size distribution measured by adynamic light scattering method. —Polymerization Inhibitor—

The curable composition forming a binder may contain a polymerizationinhibitor.

The content of the polymerization inhibitor is 0.001% to 1% by mass,more preferably 0.005% to 0.5% by mass, and still more preferably 0.008%to 0.05% by mass, with respect to all the polymerizable monomers.Changes in viscosity over time can be suppressed while maintaining ahigh curing sensitivity by blending the polymerization inhibitor in anappropriate amount. On the other hand, in the case where the amount ofthe polymerization inhibitor to be added is excessive, a curing failuredue to inhibition of polymerization and coloration of the cured productoccur, so an appropriate amount of the polymerization is present. Thepolymerization inhibitor may be added at the time of production of thepolymerizable monomer or may be added later to the curable composition.

Preferred examples of the polymerization inhibitor include hydroquinone,p-methoxyphenol, di-tert-butyl-p-cresol, pyrrogallol,tert-butylcatechol, benzoquinone,4,4′-thiobis(3-methyl-6-tert-butylphenol),2,2′-methylenebis(4-methyl-6-tert-butylphenol), cerousN-nitrosophenylhydroxyamine, phenothiazine, phenoxazine,4-methoxynaphthol, 2,2,6,6-tetramethylpiperidine-1-oxyl free radical,2,2,6,6-tetramethylpiperidine,4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical,nitrobenzene, and dimethylaniline, among which preferred isp-benzoquinone, 2,2,6,6-tetramethylpiperidine-1-oxyl free radical,4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical, orphenothiazine. These polymerization inhibitors suppress generation ofpolymer impurities not only during the production of the polymerizablemonomers but also during storage of the curable composition and suppressdegradation of pattern formability during imprinting.

—Inorganic Particles—

Further, the coating liquid for forming a fluorescent region preferablycontains inorganic particles.

Incorporation of inorganic particles can provide an enhancedimpermeability to oxygen. Examples of inorganic particles includeinorganic layered compounds such as silica particles, alumina particles,zirconium oxide particles, zinc oxide particles, titanium oxideparticles, mica, and talc.

The inorganic particles are preferably plate-like from the viewpoint ofenhancing the impermeability to oxygen. Specifically, the aspect ratio(r=a/b, where a>b) of the inorganic particles is preferably 2 to 1000,more preferably 10 to 800, and still more preferably 20 to 500. A largeraspect ratio is preferable because it has an excellent effect ofenhancing the impermeability to oxygen. However, in the case where theaspect ratio is too large, physical strength of a film or particledispersibility in a curing composition is poor.

—Light Scattering Particles—

In one aspect, the phosphor-containing layer (fluorescent region andresin layer) may contain light scattering particles. Therefore, lightscattering particles may be added to the photocurable composition.

The particle size of the light scattering particles is preferably 0.10μm or more. Incorporation of the light scattering particles in thephosphor-containing layer is preferable from the viewpoint of furtherimproving the luminance. From the viewpoint of the light scatteringeffect, the particle size of the light scattering particles ispreferably 0.10 to 15.0 μm, more preferably 0.10 to 10.0 μm, and stillmore preferably 0.20 to 4.0 μm. Two or more kinds of light scatteringparticles having different particle sizes may be mixed and used in orderto further improve the luminance and adjust the distribution of theluminance with respect to the viewing angle.

The light scattering particles may be organic particles, inorganicparticles, or organic-inorganic composite particles.

For example, synthetic resin particles can be mentioned as organicparticles. Specific examples of synthetic resin particles includesilicone resin particles, acrylic resin particles (polymethylmethacrylate (PMMA)), nylon resin particles, styrene resin particles,polyethylene particles, urethane resin particles, and benzoguanamineparticles. From the viewpoint of the light scattering effect, it ispreferable that the refractive indices of the light scattering particlesand the other portion are different in the phosphor-containing layer,and the silicone resin particles and acrylic resin particles arepreferable from the viewpoint of easy availability of particles having asuitable refractive index. Particles having a hollow structure can alsobe used.

As the inorganic particles, particles of diamond, titanium oxide,zirconium oxide, lead oxide, lead carbonate, zinc oxide, zinc sulfide,antimony oxide, silicon oxide, aluminum oxide or the like can be used.Titanium oxide and aluminum oxide are preferable from the viewpoint ofeasy availability of particles having a suitable refractive index.

In addition to the above-mentioned components, a releasing agent, asilane coupling agent, an ultraviolet absorber, a light stabilizer, ananti-aging agent, a plasticizer, an adhesion promoter, a thermalpolymerization initiator, a colorant, elastomer particles, a photoacidproliferating agent, a photobase generator, a basic compound, a flowadjusting agent, an anti-foaming agent, a dispersant, or the like may beoptionally added to the coating liquid for forming a fluorescent region.

The method for preparing the curable composition forming a binder is notparticularly limited, and it may be carried out by a procedure forpreparing a common curable composition.

<<Resin Layer Having Impermeability to Oxygen>>

The resin layer 38 (resin layer 38 having impermeability to oxygen) isformed by applying and curing a resin forming coating liquid containingthe same curable composition as the above-mentioned curable compositionforming a binder. In addition, the curable composition forming a resinlayer may not contain a polymer dispersant.

The resin layer 38 is the layer having impermeability to oxygen andpreferably satisfies an oxygen permeability of 10 cc/(m²·day·atm) orless at the shortest distance between the adjacent fluorescent regions35 with the resin layer 38 interposed therebetween. The oxygenpermeability of the resin layer 38 at the shortest distance betweenadjacent fluorescent regions 35 is more preferably 1 cc/(m²·day·atm) orless and still more preferably 1×10⁻¹ cc/(m²·day·atm) or less. Thenecessary shortest distance between the fluorescent regions 35 variesdepending on the composition of the resin layer 38.

Here, the SI unit of oxygen permeability is fm/(s·Pa). “fm” is read asfemtometer and 1 fm=1×10⁻¹⁵ m. [cc/(m²·day·atm)] can be converted intoSI unit by “1 fm/(s·Pa)=8.752 cc/(m²·day·atm).”

Depending on the composition of the resin layer 38, the shortestdistance necessary between the fluorescent regions 35 varies. Theshortest distance between adjacent fluorescent regions 35 of the resinlayer 38 refers to the shortest distance in the film plane between theadjacent fluorescent regions 35 in the case where it is observed fromthe phosphor-containing film main surface. In the following description,the shortest distance between the adjacent fluorescent regions 35 may bereferred to as the width of the resin layer.

As described above, the shortest distance necessary between thefluorescent regions 35 varies depending on the composition of the resinlayer 38, but as an example, the shortest distance between the adjacentfluorescent regions 35, that is, the width t of the resin layer 38 is 5to 300 μm, preferably 10 to 200 μm, and more preferably 15 to 100 μm. Inthe case where the width t of the resin layer 38 is too short, it isdifficult to secure the necessary oxygen permeability, and in the casewhere the width t of the resin layer 38 is too long, luminanceunevenness of a display device deteriorates, which is not preferable.

The resin layer 38 has a modulus of elasticity of preferably 0.5 to 10GPa, more preferably 1 to 7 GPa, and particularly preferably 3 to 6 GPa.By setting the modulus of elasticity of the resin layer within thisrange, it is possible to prevent defects during the formation of theresin layer 38 while maintaining oxygen permeability, which is thuspreferable.

The modulus of elasticity of the resin layer 38 is measured by a methodexemplified in JIS K7161 or the like.

The material for forming the resin layer 38 is preferably a compoundhaving a di- or higher functional photopolymerizable crosslinking group.Specifically, examples thereof include alicyclic (meth)acrylate such asurethane (meth)acrylate or tricyclodecanedimethanol di(meth)acrylate;(meth)acrylate having a hydroxyl group such as pentaerythritoltriacrylate; aromatic (meth)acrylate such as modified bisphenol Adi(meth)acrylate; dipentaerythritol di(meth)acrylate,3,4-epoxycyclohexylmethyl (meth)acrylate, 3′,4′-epoxycyclohexylmethyl3,4-epoxycyclohexane carboxylate, and bisphenol A type epoxy.

Among them, it is preferable to include at least urethane (meth)acrylateand an epoxy compound from the viewpoint of enhancing the impermeabilityto oxygen. By using a compound having a urethane bond or a polarfunctional group such as a hydroxyl group or a carboxyl group to enhanceintermolecular interaction, a resin layer having high impermeability tooxygen can be obtained.

It is preferable to include a compound having the same polymerizablecrosslinking group as that of the fluorescent region from the viewpointof excellent adhesion between the resin layer and the fluorescentregion. For example, in the case where dicyclopentanyl (meth)acrylate orthe like is contained in the material of the fluorescent region, theresin layer preferably contains at least a (meth)acrylate compound.

(Additives)

The resin layer forming material may optionally contain aphotopolymerization initiator, an inorganic layered compound, lightscattering particles, an antioxidant, a release promoter, a solvent, andthe like.

(Photopolymerization Initiator)

The curable compound forming the resin layer 38 preferably contains aphotopolymerization initiator. Any photopolymerization initiator may beused as long as it is a compound capable of generating an active speciesthat polymerizes the polymerizable compound upon irradiation of light.Examples of the photopolymerization initiator include a cationicpolymerization initiator and a radical polymerization initiator, whichare appropriately selected according to the resin layer formingmaterial.

(Inorganic Layered Compound)

The curable compound forming the resin layer 38 may contain a compoundthat imparts a so-called maze effect, such as an inorganic layeredcompound, which extends the diffusion length of gas molecules in theresin layer to improve gas barrier properties. Examples of such aninorganic layered compound include talc, mica, feldspar, kaolinite(kaolin clay), pyrophyllite (pyrophyllite clay), sericite (silk mica),bentonite, smectite-vermiculites (montmorillonite, beidellite,non-tronite, saponite, and the like), organic bentonite, organicsmectite, and flat inorganic oxide such as flat alumina. The inorganiclayered compound may be subjected to a surface treatment in order toimprove dispersibility in the resin forming material.

Further, from the viewpoint of the excellent maze effect describedabove, the inorganic layered compound preferably has an aspect ratio of10 to 1000. In the case where the aspect ratio is 10 or less, the effectof improving the gas barrier property due to the maze effect is low, andin the case where the aspect ratio is 1000 or more, the inorganiclayered compound is brittle and therefore may be crushed during theproduction process.

These layered compounds can be used alone or in combination of two ormore thereof. Examples of commercially available layered compounds asthe inorganic compound include ST-501 and ST-509 (manufactured byShiraishi Calcium Kaisha, Ltd.), SOMASIF series and Micro Mica series(manufactured by Katakura & Co-op Agri Corporation), and SERAPH series(manufactured by Kinsei Matec Co., Ltd.). In particular, in thephosphor-containing film according to the embodiment of the presentinvention, a SERAPH series having high transparency can be suitablyused.

Here, in a case where the resin layer 38, that is, the curable compoundforming the resin layer 38 contains the inorganic layered compound, itis preferable to increase the thickness b of the bottom of the concaveportion of the resin layer 38.

Specifically, in a case where the resin layer 38 contains the inorganiclayered compound, the thickness b of the bottom of the concave portionof the resin layer 38 is preferably 1 μm or more, and more preferablythicker than the maximum length of the inorganic layered compound.

In a case where the resin layer 38 contains the inorganic layeredcompound, the thickness b of the bottom of the concave portion of theresin layer 38 is made thicker, such that damage to the inorganic layerof the barrier layer 12 can be more suitably prevented at the time offorming the concave portion (concavity-convexity) of the resin layer 38by molding and deterioration of the phosphor 31 caused by oxygen or thelike can be prevented, which makes it possible to obtain aphosphor-containing film with high durability.

In the phosphor-containing layer 30, the ratio of the volume Vp of thefluorescent region 35 to the volume Vb of the resin layer 38 can beoptional, but the ratio of the volume Vp of the fluorescent region 35 tothe volume (Vp+Vb) of the entire phosphor-containing layer is preferably0.1≤Vp/(Vp+Vb)<0.9, more preferably 0.2≤Vp/(Vp+Vb)<0.85, and still morepreferably 0.3≤Vp/(Vp+Vb)<0.8.

In the phosphor-containing layer 30, in the case where the volume ratioof the fluorescent region 35 is too small, the initial luminance at acertain thickness tends to decrease, and in the case where the volumeratio of the fluorescent region 35 is too large, the width of the resinlayer 38 becomes short, and as a result, it becomes difficult to securethe necessary oxygen permeability. Note that a region Vp containingphosphors and a region Vb of a resin layer having oxygen impermeabilityare defined as being multiplied by each area and thickness in the casewhere observed from the phosphor-containing film main surface.—Substrate Film—

The first substrate film 10 and the second substrate film 20 arepreferably a film having a function of suppressing permeation of oxygen.The above-mentioned embodiment, the first substrate film 10 and thesecond substrate film 20 have a configuration in which the barrierlayers 12 and 22 are provided on one surface of the support films 11 and21, respectively. In such an embodiment, the presence of the supportfilms 11 and 21 improves the strength of the phosphor-containing filmand makes it possible to easily perform film formation. In the presentembodiment, the barrier layers 12 and 22 are provided on one surface ofthe support films 11 and 21, but the substrate film may be constitutedby only a support having sufficient barrier properties.

The first substrate film 10 and the second substrate film 20 have atotal light transmittance in the visible light region of preferably 80%or more and more preferably 85% or more. The visible light region refersto a wavelength range of 380 to 780 nm, and the total lighttransmittance refers to an average value of light transmittances overthe visible light region.

The oxygen permeability of the first substrate film 10 and the secondsubstrate film 20 is preferably 1 cc/(m²·day·atm) or less. The oxygenpermeability of the first substrate film 10 and the second substratefilm 20 is more preferably 0.1 cc/(m²·day·atm) or less, still morepreferably 0.01 cc/(m²·day·atm) or less, and particularly preferably0.001 cc/(m²·day·atm) or less. The oxygen permeability here is a valuemeasured using an oxygen gas permeability measuring apparatus (OX-TRAN2/20, trade name, manufactured by MOCON Inc.) under conditions of ameasurement temperature of 23° C. and a relative humidity of 90%.

In addition to having a gas barrier function of blocking oxygen, thefirst substrate film 10 and the second substrate film 20 preferably havea function of blocking moisture (water vapor). The moisture permeability(water vapor permeability) of the first substrate film 10 and the secondsubstrate film 20 is preferably 0.10 g/(m²·day·atm) or less and morepreferably 0.01 g/(m²·day·atm) or less.

(Support Film)

The support films 11 and 21 are preferably a flexible belt-like supportwhich is transparent to visible light. The phrase “transparent tovisible light” as used herein refers to a light transmittance in thevisible light region of 80% or more and preferably 85% or more. Thelight transmittance for use as a measure of transparency can becalculated by the method described in JIS-K7105, namely, by measuring atotal light transmittance and an amount of scattered light using anintegrating sphere type light transmittance measuring apparatus, andsubtracting the diffuse transmittance from the total lighttransmittance. With respect to the flexible support, reference can bemade to paragraphs [0046] to [0052] of JP2007-290369A and paragraphs[0040] to [0055] of JP2005-096108A.

The support film preferably has barrier properties against oxygen andmoisture. Preferred examples of such a support film include apolyethylene terephthalate film, a film made of a polymer having acyclic olefin structure, and a polystyrene film.

The average film thickness of the support films 11 and 21 is preferably10 to 500 μm, more preferably 20 to 400 μm, and still more preferably 30to 300 μm from the viewpoint of impact resistance of thephosphor-containing film or the like.

Since it is preferable that the absorbance of light having a wavelengthof 450 nm is lower in an aspect of increasing the retroreflection oflight as in the case where the concentration of the quantum dotscontained in the phosphor-containing layer 30 is reduced or in the casewhere the thickness of the phosphor-containing layer 30 is reduced, theaverage film thickness of the support films 11 and 21 is preferably 40μm or less and more preferably 25 μm or less from the viewpoint ofsuppressing reduction in luminance.

Further, in the support films 11 and 21, the in-plane retardation Re(589) at a wavelength of 589 nm is preferably 1000 nm or less, morepreferably 500 nm or less, and still more preferably 200 nm or less.

In the case of inspecting the presence or absence of foreign matters anddefects after preparing the phosphor-containing film, arranging twopolarizing plates at the extinction position, inserting aphosphor-containing film therebetween and observing it makes it easy tofind foreign matters and defects. In the case where the Re (589) of thesupport is within the above range, foreign matters and defects are moreeasily found at the time of inspection using a polarizing plate, whichis thus preferable.

Here, the Re (589) can be measured by making light having an inputwavelength of 589 nm incident in the normal direction of the film usingan AxoScan OPMF-1 (manufactured by Opto Science, Inc.).

(Barrier Layer)

The first substrate film 10 and the second substrate film 20 preferablycomprise barrier layers 12 and 22 containing at least one inorganiclayer formed in contact with the surface of the support films 11 and 21on the phosphor-containing layer 30 side. The barrier layers 12 and 22may include at least one inorganic layer and at least one organic layer(see FIGS. 15 and 16). Lamination of a plurality of layers in this wayis preferable from the viewpoint of improving the light resistance dueto being capable of further more enhancing barrier properties. On theother hand, the light transmittance of the substrate film tends todecrease as the number of layers to be laminated is increased, andtherefore it is desirable to increase the number of laminated layers aslong as a satisfactory light transmittance can be maintained.

The barrier layers 12 and 22 preferably have a total light transmittancein the visible light region of preferably 80% or more and an oxygenpermeability of 1.00 cc/(m²·day·atm) or less.

The oxygen permeability of the barrier layers 12 and 22 is morepreferably 0.1 cc/(m²·day·atm) or less, particularly preferably 0.01cc/(m²·day·atm) or less, and more particularly preferably 0.001cc/(m²·day·atm) or less.

A lower oxygen permeability is more preferable, and a higher total lighttransmittance in the visible light region is more preferable.

—Inorganic Layer—

The inorganic layer is a layer containing an inorganic material as amain component, is preferably a layer in which the inorganic materialoccupies 50% by mass or more, further 80% by mass or more, particularly90% by mass or more, and is preferably a layer formed from only aninorganic material.

The inorganic layer is preferably a layer having a gas barrier functionof blocking oxygen. Specifically, the oxygen permeability of theinorganic layer is preferably 1 cc/(m²·day·atm) or less. The oxygenpermeability of the inorganic layer can be determined by attaching awavelength converting layer to a detector of an oxygen concentrationmeter manufactured by Orbisphere Laboratories, via silicone grease, andthen converting the oxygen permeability from the equilibrium oxygenconcentration value. It is also preferable that the inorganic layer hasa function of blocking water vapor.

Two or three or more inorganic layers may also be included in thebarrier layer.

The thickness of the inorganic layer may be 1 to 500 nm, and ispreferably 5 to 300 nm and particularly preferably 10 to 150 nm. This isbecause the film thickness of an adjacent inorganic layer in the aboverange is capable of suppressing reflection on the inorganic layer whileachieving satisfactory barrier properties, whereby a laminated film withhigher light transmittance can be provided.

The inorganic material constituting the inorganic layer is notparticularly limited, and for example, a metal, or various inorganiccompounds such as inorganic oxides, nitrides or oxynitrides can be usedtherefor. For element(s) constituting the inorganic material, silicon,aluminum, magnesium, titanium, tin, indium, and cerium are preferable,and these elements may be included singly or two or more thereof may beincluded. Specific examples of the inorganic compound include siliconoxide, silicon oxynitride, aluminum oxide, magnesium oxide, titaniumoxide, tin oxide, an indium oxide alloy, silicon nitride, aluminumnitride, and titanium nitride. As the inorganic layer, a metal film, forexample, an aluminum film, a silver film, a tin film, a chromium film, anickel film, or a titanium film may also be provided.

It is particularly preferable that the inorganic layer having barrierproperties is an inorganic layer containing at least one compoundselected from silicon nitride, silicon oxynitride, silicon oxide, oraluminum oxide, among the above-mentioned materials. This is because theinorganic layer formed of such a material is satisfactory inadhesiveness to the organic layer, and therefore, not only, even in thecase where the inorganic layer has a pinhole, the organic layer caneffectively fill in the pinhole to suppress fracture, but also, even inthe case where the inorganic layer is laminated, an extremelysatisfactory inorganic layer film can be formed to result in a furtherenhancement in barrier properties. From the viewpoint of suppressingabsorption of light in the barrier layer, silicon nitride is mostpreferable.

The method for forming an inorganic layer is not particularly limited,and for example, a variety of film forming methods capable ofevaporating or scattering a film forming material and depositing it onthe deposition target surface can be used.

Examples of the method of forming an inorganic layer include a physicalvapor deposition method (PVD method) such as a vacuum vapor depositionmethod of heating an inorganic material such as an inorganic oxide, aninorganic nitride, an inorganic oxynitride, or a metal to cause vapordeposition thereof; an oxidation reaction vapor deposition method ofusing an inorganic material as a starting material and introducingoxygen gas for oxidation to cause vapor deposition thereof; a sputteringmethod of using an inorganic material as a target starting material andintroducing argon gas or oxygen gas for sputtering to cause vapordeposition; or an ion plating method of causing heating of an inorganicmaterial by a plasma beam generated by a plasma gun to cause vapordeposition. An example of a method of forming a vapor deposited film ofsilicon oxide includes a plasma chemical vapor deposition method (CVDmethod) of using an organosilicon compound as a starting material.

Furthermore, an example of a method of forming a vapor deposited film ofsilicon nitride as the inorganic layer includes the plasma CVD method ofusing a silane gas as a starting material.

—Organic Layer—

The organic layer refers to a layer containing an organic material as amain component, in which the organic material preferably occupies 50% bymass or more, further preferably 80% by mass or more, and particularlypreferably 90% by mass or more.

With respect to the organic layer, reference can be made to paragraphs[0020] to [0042] of JP2007-290369A and paragraphs [0074] to [0105] ofJP2005-096108A. It is preferable that the organic layer contains a cardopolymer within a range satisfying the above-mentioned adhesion forceconditions. This is because adhesiveness to the layer adjacent to theorganic layer, in particular, also adhesiveness to the inorganic layercan be thus improved to achieve excellent gas barrier properties. Withrespect to details of the cardo polymer, reference can be made toparagraphs [0085] to [0095] of JP2005-096108A described above.

The film thickness of the organic layer is preferably in the range of0.05 to 10 μm, inter alia, preferably in the range of 0.5 to 10 μm. Inthe case where the organic layer is formed by a wet coating method, thefilm thickness of the organic layer is preferably in the range of 0.5 to10 μm, inter alia, preferably in the range of 1 to 5 μm. In the casewhere the organic layer is formed by a dry coating method, the filmthickness of the organic layer is preferably in the range of 0.05 to 5μm, inter alia, preferably in the range of 0.05 to 1 μm. This is becausethe film thickness of the organic layer formed by a wet coating methodor a dry coating method in the above-specified range is capable offurther improving adhesiveness to the inorganic layer.

With respect to other details of the inorganic layer and the organiclayer, reference can be made to the descriptions of JP2007-290369A andJP2005-096108A described above and US2012/0113672A1.

In the phosphor-containing film, the organic layer may be laminated asthe underlayer of the inorganic layer between the support film and theinorganic layer, and may be laminated as the protective layer of theinorganic layer between the inorganic layer and the phosphor-containinglayer. Further, in the case of having two or more inorganic layers, theorganic layer may be laminated between the inorganic layers.

(Concavity-Convexity Imparting Layer)

The substrate films 10 and 20 may be provided with a concavity-convexityimparting layer for imparting a concave-convex structure on the surfaceopposite to the surface on the phosphor-containing layer 30 side. In thecase where the substrate films 10 and 20 have a concavity-convexityimparting layer, the blocking property and sliding property of thesubstrate film can be improved, which is thus preferable. Theconcavity-convexity imparting layer is preferably a layer containingparticles. Examples of the particles include inorganic particles such assilica, alumina, or metal oxide, and organic particles such ascrosslinked polymer particles. The concavity-convexity imparting layeris preferably provided on the surface opposite to thephosphor-containing layer of the substrate film, but it may be providedon both surfaces.

The phosphor laminate film can have a light scattering function toefficiently extract the fluorescence of quantum dots to the outside. Thelight scattering function may be provided inside the phosphor-containinglayer 30 or a layer having a light scattering function may be separatelyprovided as the light scattering layer. The light scattering layer maybe provided on the surface on the side of the phosphor-containing layer30 of the substrate films 10 and 20 or may be provided on the surface onthe side opposite to the phosphor-containing layer 30 of the substratefilms 10 and 20. In the case where the concavity-convexity impartinglayer is provided, it is preferable that the concavity-convexityimparting layer is a layer which can also serve as the light scatteringlayer.

<Production Method of Phosphor-Containing Film>

Next, an example of production steps of the phosphor-containing filmaccording to the embodiment of the present invention configured asdescribed above will be described with reference to FIGS. 11 and 12.

(Coating Liquid Preparation Step)

In the first coating liquid preparation step, a coating liquid forforming a fluorescent region containing quantum dots (or quantum rods)as phosphors is prepared. Specifically, individual components such asquantum dots, a curable compound, a polymer dispersant, a polymerizationinitiator, and a silane coupling agent dispersed in an organic solventare mixed in a tank or the like to prepare a coating liquid for forminga fluorescent region. Note that the coating liquid for forming afluorescent region may not contain an organic solvent.

In the second coating liquid preparation step, a coating liquid for aresin layer to be filled between the fluorescent regions is prepared.

(Resin Layer Forming Step)

Next, a coating liquid for a resin layer is applied onto the firstsubstrate film 10, the coating liquid for the resin layer is dried asneeded, and then a mold having a concavo-convex pattern is pressedagainst the applied coating liquid for a resin layer (coating film) toform a predetermined pattern having a concave portion, and the coatingliquid for a resin layer is cured to form a laminated film 59 in whichthe resin layer 38 having a plurality of concave portions is laminatedon the first substrate film 10, as shown in FIG. 11.

Here, in the phosphor-containing film according to the embodiment of thepresent invention, a resin layer 38 having a plurality of concaveportions is formed such that the thickness of the bottom of the concaveportion of the resin layer 38 is 0.1 to 20 μm. In this way, the presentinvention can realize a phosphor-containing film having high durabilitywhere contact between the mold and the first substrate film 10 isprevented, damage to the inorganic layer of the barrier layer 12 of thefirst substrate film 10 is prevented, and deterioration of the phosphor31 caused by oxygen or the like is prevented.

(Fluorescent Region Forming Step and Second Substrate Film Bonding Step)

Next, the coating liquid for forming a fluorescent region is appliedinto the concave portion of the resin layer 38 of the laminated film 59,the second substrate film 20 is bonded before curing the coating liquidfor forming a fluorescent region, and then the coating liquid forforming a fluorescent region is cured to form a fluorescent region 35 toprepare a phosphor-containing film in which the first substrate film 10,the phosphor-containing layer 30, and the second substrate film 20 arelaminated as shown in FIG. 12.

With respect to the curing treatment in the fluorescent region formingstep and the resin layer forming step, thermal curing, photocuring withultraviolet rays, or the like may be appropriately selected depending onthe coating liquid.

In the case where the resin layer 38 is cured by photocuring withultraviolet rays, the irradiation amount of ultraviolet rays ispreferably 100 to 10000 mJ/cm².

On the other hand, in the case where the resin layer 38 is cured bythermal curing, it is preferable to heat the resin layer 38 to 20° C. to100° C.

(Cutting Process)

The obtained phosphor-containing film is cut by a cutting machine asnecessary.

Incidentally, as for the method for preparing the phosphor-containingfilm, each of the above-described steps may be carried out continuouslyby a so-called roll-to-roll (RtoR), or alternatively, the treatment ofeach step may be carried out in a so-called single wafer type using thesubstrate film in the form of a cut sheet.

Here, a method of forming a plurality of concave portions(concavo-convex pattern) in the coating liquid for a resin layer appliedto the first substrate film 10 will be specifically described.

As the formation of the pattern, as described above, it is possible touse a method of forming a fine concavo-convex pattern by pressing a moldhaving a concavo-convex pattern against a coating liquid for a resinlayer applied onto a substrate film.

Pattern formation can also be carried out by an ink jet method or adispenser method.

The mold usable herein is a mold having formed thereon a pattern to betransferred. The pattern on the mold may be formed according to desiredprocessing accuracy, for example, by photolithography, electron beamlithography, or the like, but the method of forming a mold pattern isnot particularly limited.

The light-transmissive molding material is not particularly limited, butany material having predetermined strength and durability may be used.Specific examples thereof include glass, quartz, a light-transparentresin such as PMMA or polycarbonate resin, a transparent metalvapor-deposited film, a flexible film made of polydimethylsiloxane orthe like, a photocured film, and a metal film such as SUS.

On the other hand, the non-light-transmissive molding material is notparticularly limited, but any material having a predetermined strengthmay be used. Specific examples of the molding material include a ceramicmaterial, a vapor deposited film, a magnetic film, a reflective film, ametal substrate such as Ni, Cu, Cr, Fe or the like, and a substrate ofSiC, silicon, silicon nitride, polysilicon, silicon oxide, amorphoussilicon or the like. Further, the shape of the mold is not particularlylimited, either a plate-like mold or a roll-like mold may be used. Theroll-like mold is applied particularly in the case where continuousproductivity of transfer is required.

A mold may be used which has been subjected to a surface releasetreatment in order to improve releasability between the curable compoundand the mold surface. Such a mold may be, for example, a mold coatedwith a material having excellent water and oil repellency. Specifically,those in which polytetrafluoroethylene (PTFE), diamond-like carbon(DLC), or the like is vapor-deposited by physical vapor deposition (PVD)or chemical vapor deposition (CVD), and those treated with a silanecoupling agent such as a silicone-based silane coupling agent or afluorine-based silane coupling agent are exemplified. For example,commercially available releasing agents such as OPTOOL DSX (manufacturedby Daikin Industries, Ltd.) and Novec EGC-1720 (manufactured by Sumitomo3M Ltd.) can also be suitably used for releasing treatment.

Specific examples of a method for forming the concavo-convex patternusing the mold include a thermal imprinting method in which a mold ispressed against a resin layer applied and cured on a substrate film in astate where the resin layer or the mold is heated to form a fineconcavo-convex pattern; a photoimprinting method in which a mold havinga concavo-convex pattern is pressed against a coating liquid for a resinlayer applied on a substrate film, and then the resin layer is curedwith light to form a fine concavo-convex pattern; and a melt-moldingmethod for forming a fine concavo-convex pattern. Among them, aphotoimprinting method is preferable from the viewpoint of excellentproduction rate and low capital investment.

In the case where photoimprint lithography is carried out, it is usuallypreferable to carry out the lithography at a mold pressure of 10 atm orless. In the case where the mold pressure is set to 10 atm or less, themold and the substrate are hardly deformed and the pattern accuracytends to improve. In addition, it is preferable from the viewpoint thatthe pressure unit may be small-sized since the pressure to be given tothe mold may be low. Regarding the mold pressure, it is preferable toselect a region where uniformity of mold transfer can be secured withinthe range where the residual film of the curable compound in the area ofmold pattern projections is reduced.

The irradiation dose of photo-irradiation at the time of curing thecurable compound may be sufficiently larger than the irradiation dosenecessary for curing. The irradiation dose necessary for curing isappropriately determined by examining the consumption amount ofunsaturated bonds of the curable composition and the tackiness of thecured film.

In the photoimprint lithography, photo-irradiation is carried out whilekeeping the substrate temperature generally at room temperature, inwhich the photo-irradiation may alternatively be conducted under heatingfor the purpose of enhancing the reactivity. The photo-irradiation maybe carried out in vacuo, since a vacuum conditioning prior to thephoto-irradiation is effective for preventing entrainment of bubbles,suppressing the reactivity from being reduced due to incorporation ofoxygen, and for improving the adhesiveness between the mold and thecurable composition. In the pattern forming method, the degree of vacuumat the time of photo-irradiation is preferably in the range of 10⁻¹ Pato 1 atmosphere.

The light used for curing the curable compound is not particularlylimited, and examples thereof include light and radiation having awavelength falling within a range of high-energy ionizing radiation,near ultraviolet light, far ultraviolet light, visible light, infraredlight, and the like. The high-energy ionizing radiation source includes,for example, accelerators such as a Cockcroft accelerator, a Van deGraaff accelerator, a linear accelerator, a betatron, and a cyclotron.The electron beams accelerated by such an accelerator are usedindustrially most conveniently and economically. Any other radioisotopesand other radiations from nuclear reactors, such as γ-rays, X-rays,α-rays, neutron beams, and proton beams may also be used.

Examples of the ultraviolet ray source include an ultravioletfluorescent lamp, a low-pressure mercury lamp, a high-pressure mercurylamp, an ultra-high-pressure mercury lamp, a xenon lamp, a carbon arclamp, a solar lamp, and a light emitting diode (LED).

Examples of the radiation include microwaves and extreme ultraviolet(EUV).

In addition, laser light used in microfabrication of semiconductors,such as LED, semiconductor laser light, 248 nm KrF excimer laser light,and 193 nm ArF excimer laser light, can also be suitably used in thepresent invention.

These light rays may be monochromatic light, or may also be a pluralityof light rays of different wavelengths (mixed light).

Upon exposure, the exposure illuminance is preferably within a range of1 to 1000 mW/cm². In the case where the exposure illuminance is set to 1mW/cm² or more, then the productivity may increase since the exposuretime may be reduced; and in the case where the exposure illuminance isset to 1000 mW/cm² or less, then it is preferable since the propertiesof a permanent film may be prevented from being degraded owing to sidereactions.

The exposure dose is preferably in the range of 5 mJ/cm² to 10,000mJ/cm². In the case where the exposure dose is less than 5 mJ/cm², theexposure margin becomes narrow and the photocuring becomes insufficientso that problems such as adhesion of unreacted materials to the mold areliable to occur. On the other hand, in the case where the exposure doseis more than 10,000 mJ/cm², there is a risk of deterioration of thepermanent film due to decomposition of the composition.

Further, at the time of exposure, in order to prevent inhibition ofradical polymerization by oxygen, an inert gas such as nitrogen or argonmay be flowed to control the oxygen concentration to be less than 100mg/L.

In curing the curable compound, after the curable compound is curedthrough photo-irradiation, a step of further curing the curable compoundby applying heat thereto may be included as necessary. The temperatureof heat for curing with heating after photo-irradiation is preferably80° C. to 280° C. and more preferably 100° C. to 200° C. The time forapplying heat is preferably 5 to 60 minutes and more preferably 15 to 45minutes.

The concavo-convex pattern formed in the resin layer 38 can take anyform.

As the concavo-convex pattern, for example, there are a grid-like meshpattern in which the opening shape of the concave portion or the shapeof the convex portion is regular quadrangular or rectangular; ahoneycomb pattern in which a concave portion or a convex portion isregular hexagonal; a sea island pattern in which a concave portion or aconvex portion is circular; a compound pattern such as a combination ofa regular pentagon/a regular hexagon as a concave portion or a convexportion, a combination of regular polygons called Archimedes' planarfilling, or a combination of circular shapes with different diameters;and a pattern with in-plane distribution in size of hexagon.

Among them, from the viewpoint of suppressing defects of a septum at thetime of releasing a resin layer from a mold in the case of forming theresin layer 38 by a photoimprinting method, of shortening the ingressdistance, or the like, a regular polygonal pattern such as a square orregular hexagonal pattern, and a circular pattern are preferable. Inaddition, a regular hexagonal pattern is more preferable from theviewpoint of increasing the filling ratio (area ratio) of thefluorescent region 35.

Further, in the above example, the step of curing the resin layer 38 iscarried out in a state where the mold is closely attached, but it may becarried out after peeling of the mold. It is preferable to carry out thestep of curing the resin layer 38 in a state where the mold is closelyattached.

In the case of carrying out a thermal imprinting method, it is usuallypreferably carried out at a mold pressure in the range of 0.1 to 100MPa. In addition, it is preferable to set the temperature of the moldand the resin layer within a predetermined range. Generally, it is oftento set the mold temperature to be equal to or higher than the glasstransition temperature (Tg) of the resin layer, and set the substratetemperature lower than the mold temperature.

In the case of carrying out a melt molding method, a resin to be moldedis heated to a temperature equal to or higher than the melting pointthereof, and the resin (melt) in a molten state is immediately flowedbetween the mold and the substrate film, followed by pressing andcooling to prepare a molded article. A polymer having a low oxygenpermeability is preferable as a material suitable for the resin layer 38in the case of carrying out the melt molding method. Specific examplesof such a polymer include polyester resins such as polyvinyl alcohol(PVA), polyethylene-vinyl alcohol copolymer (EVOH), polyvinylidenechloride (PVDC), polyvinylidene fluoride (PVDF), and polyethyleneterephthalate (PET). Among them, (modified) polyvinyl alcohol ispreferable and polyethylene-vinyl alcohol copolymer (EVOH) isparticularly preferable from the viewpoint of excellent transparency andexcellent heat resistance and light resistance.

An anchor coat layer may be provided on the substrate film in order toensure adhesiveness with the substrate film forming the resin layer. Thematerial of the anchor coat layer is appropriately selected according tothe material of the resin layer 38 and the substrate film. For example,in the case where the resin layer is EVOH and the substrate film is PET,a urethane-based compound, a polyethyleneimine-based compound, apolybutadiene-based compound, a (modified) polyolefin-based compound orthe like can be mentioned as the material of the anchor coat layer. Fromthe viewpoint of excellent water resistance and adhesion force, ananchor coat material of a urethane-based compound, a (modified)polyolefin-based compound or the like is most preferable. Specificexamples of commercially available products of the anchor coat materialinclude EL-530A/B (manufactured by Toyo-Morton, Ltd.), and TAKELACA/TAKENATE A series, ADMER series, UNISTOLE series (all manufactured byMitsui Chemicals, Inc.).

“Backlight Unit”

With reference to the drawings, a description will be given of abacklight unit comprising a wavelength converting member as oneembodiment of the phosphor-containing film of the present invention.FIG. 13 is a schematic diagram showing a schematic configuration of abacklight unit.

As shown in FIG. 13, the backlight unit 102 comprises a planar lightsource 101C including a light source 101A that emits primary light (bluelight L_(B)) and a light guide plate 101B that guides and emits primarylight emitted from the light source 101A, a wavelength converting member100 made of a phosphor-containing film provided on the planar lightsource 101C, a reflecting plate 102A disposed opposite to the wavelengthconverting member 100 with the planar light source 101C interposedtherebetween, and a retroreflective member 102B. In FIG. 13, thereflecting plate 102A, the light guide plate 101B, the wavelengthconverting member 100, and the retroreflective member 102B are separatedfrom each other, but in reality these may be formed in intimateattachment with each other.

The wavelength converting member 100 emits fluorescence by using atleast a part of the primary light L_(B) emitted from the planar lightsource 101C as excitation light and emits the secondary light (greenlight L_(G) and red light L_(R)) composed of this fluorescence and theprimary light L_(B) transmitted through the wavelength converting member100. For example, the wavelength converting member 100 is aphosphor-containing film which is constituted such that thephosphor-containing layers including the quantum dots that emit thegreen light L_(G) and the quantum dots that emit the red light L_(R)upon irradiation with the blue light L_(B) are sandwiched between thefirst substrate film 10 and the second substrate film 20.

In FIG. 13, L_(B), L_(G), and L_(R) emitted from the wavelengthconverting member 100 are incident on the retroreflective member 102B,and each incident light repeats reflection between the retroreflectivemember 102B and the reflecting plate 102A and passes through thewavelength converting member 100 many times. As a result, in thewavelength converting member 100, a sufficient amount of excitationlight (blue light L_(B)) is absorbed by the phosphors 31 (in this case,quantum dots) in the phosphor-containing layer 30 and a necessary amountof fluorescence (L_(G) and L_(R)) is emitted, and the white light L_(W)is embodied from the retroreflective member 102B and is emitted.

From the viewpoint of realizing high luminance and high colorreproducibility, it is preferable to use, as the backlight unit, oneformed into a multi-wavelength light source. For example, preferred is abacklight unit which emits blue light having a luminescence centerwavelength in the wavelength range of 430 to 480 nm and having aluminescence intensity peak with a half-width of 100 nm or less, greenlight having a luminescence center wavelength in the wavelength range of500 to 600 nm and having a luminescence intensity peak with a half-widthof 100 nm or less, and red light having a luminescence center wavelengthin the wavelength range of 600 to 680 nm and having a luminescenceintensity peak with a half-width of 100 nm or less.

From the viewpoint of further improving luminance and colorreproducibility, the wavelength range of the blue light emitted from thebacklight unit is more preferably 440 to 460 nm.

From the same viewpoint, the wavelength range of the green light emittedfrom the backlight unit is preferably 520 to 560 nm and more preferably520 to 545 nm.

In addition, from the same viewpoint, the wavelength range of the redlight emitted from the backlight unit is more preferably 610 to 640 nm.

In addition, from the same viewpoint, all the half-widths of therespective luminescence intensities of the blue light, the green light,and the red light emitted from the backlight unit are preferably 80 nmor less, more preferably 50 nm or less, further preferably 40 nm orless, still more preferably 30 nm or less. Among them, the half-width ofthe luminescence intensity of the blue light is particularly preferably25 nm or less.

In the above description, the light source 101A is, for example, a bluelight emitting diode that emits blue light having a luminescence centerwavelength in the wavelength range of 430 to 480 nm, but an ultravioletlight emitting diode that emits ultraviolet light may be used. As thelight source 101A, a laser light source or the like may be used inaddition to light emitting diodes. In the case where a light source thatemits ultraviolet light is provided, the wavelength converting layer(phosphor-containing layer) of the wavelength converting member mayinclude a phosphor that emits blue light, a phosphor that emits greenlight, and a phosphor that emits red light, upon irradiation withultraviolet light.

As shown in FIG. 13, the planar light source 101C may be a planar lightsource formed of the light source 101A, and the light guide plate 101Bwhich guides the primary light exiting from the light source 101A andallows the guided primary light to exit, or may be a planar light sourcein which the light source 101A and the wavelength converting member 100are disposed parallel to each other on the plane, and a diffusion plateis provided in place of the light guide plate 101B. The former planarlight source is generally referred to as an edge light mode backlightunit, and the latter planar light source is generally referred to as adirect backlight mode backlight unit.

In the present embodiment, the case where a planar light source is usedas a light source has been described as an example, but a light sourceother than the planar light source may also be used as the light source.

(Configuration of Backlight Unit)

In FIG. 13, an edge light mode backlight unit including a light guideplate, a reflecting plate, and the like as constituent members has beenillustrated as the configuration of the backlight unit, but thebacklight unit may be a direct backlight mode backlight unit. A knownlight guide plate can be used without any limitation as the light guideplate.

In addition, the reflecting plate 102A is not particularly limited, andknown reflecting plates can be used, which are described in JP3416302B,JP3363565B, JP4091978B, and JP3448626B, and the like, the contents ofwhich are incorporated by reference herein in their entirety.

The retroreflective member 102B may be configured of a known diffusionplate or a known diffusion sheet, a known prism sheet (for example, BEFseries manufactured by Sumitomo 3M Limited), a known light guide device,and the like. The configuration of the retroreflective member 102B isdescribed in JP3416302B, JP3363565B, JP4091978B, JP3448626B, and thelike, the contents of which are incorporated by reference herein intheir entirety.

“Liquid Crystal Display”

The backlight unit 102 described above can be applied to a liquidcrystal display. FIG. 14 is a schematic diagram showing a schematicconfiguration of a liquid crystal display.

As shown in FIG. 14, a liquid crystal display 104 comprises thebacklight unit 102 of the above-described embodiment, and a liquidcrystal cell unit 103 disposed opposite to the retroreflective memberside of the backlight unit.

As shown in FIG. 14, the liquid crystal cell unit 103 has aconfiguration in which a liquid crystal cell 110 is sandwiched betweenpolarizing plates 120 and 130, and the polarizing plates 120 and 130 areconfigured such that both main surfaces of polarizers 122 and 132 areprotected by polarizing plate protective films 121 and 123, and 131 and133, respectively.

The liquid crystal cell 110 and the polarizing plates 120 and 130constituting the liquid crystal display 104 and the constituents thereofare not particularly limited, and members prepared by a known method orcommercially available products can be used without any limitation. Inaddition, it is also possible, of course, to provide a knownintermediate layer such as an adhesive layer between the respectivelayers.

A driving mode of the liquid crystal cell 110 is not particularlylimited, and various modes such as a twisted nematic (TN) mode, a supertwisted nematic (STN) mode, a vertical alignment (VA) mode, an in-planeswitching (IPS) mode, and an optically compensated bend cell (OCB) modecan be used. The driving mode of the liquid crystal cell is preferably aVA mode, an OCB mode, an IPS mode, or a TN mode, but it is not limitedthereto. An example of the configuration of the liquid crystal displayin the VA mode may be the configuration illustrated in FIG. 2 ofJP2008-262161A. Here, a specific configuration of the liquid crystaldisplay is not particularly limited, and a known configuration can beadopted.

Further, as necessary, the liquid crystal display 104 includes asubsidiary functional layer such as an optical compensation memberperforming optical compensation or an adhesive layer. In addition, asurface layer such as a forward scattering layer, a primer layer, anantistatic layer, or an undercoat layer may be disposed along with (orin place of) a color filter substrate, a thin layer transistorsubstrate, a lens film, a diffusion sheet, a hard coat layer, anantireflection layer, a low reflective layer, an antiglare layer, or thelike.

The backlight side polarizing plate 120 may include a phase differencefilm as a polarizing plate protective film 123 on the liquid crystalcell 110 side. A known cellulose acylate film or the like can be used assuch a phase difference film.

The backlight unit 102 and the liquid crystal display 104 are providedwith the wavelength converting member made of the phosphor-containingfilm according to the embodiment of the present invention describedabove. Accordingly, a high-luminance backlight unit and a high-luminanceliquid crystal display, which exhibit the same effect as that of theabove-mentioned phosphor-containing film according to the embodiment ofthe present invention and in which the luminescence intensity of thewavelength converting layer containing quantum dots is hardly lowered,are obtained.

EXAMPLES

Hereinafter, the present invention will be more specifically describedwith reference to Examples. The materials, use amounts, proportions,treatment contents, treatment procedures, and the like shown in thefollowing Examples can be appropriately modified without departing fromthe spirit of the present invention. Therefore, the scope of the presentinvention should not be construed as being limited to the followingspecific Examples.

Example 1

<Preparation of Phosphor-Containing Film>

A phosphor-containing film having a phosphor-containing layer wasprepared using a coating liquid containing quantum dots as a phosphor.

(Preparation of Barrier Film)

As a first substrate film and a second substrate film, a barrier filmwas prepared in which a barrier layer made of an inorganic layer wasformed on a support film made of PET, and an organic layer coated withthe following composition was formed on the barrier layer was preparedas follows.

Using a PET film (manufactured by Toyobo Co., Ltd., trade name“COSMOSHINE (registered trademark) A4300”, thickness: 23 μm) as asupport, an organic layer and an inorganic layer were sequentiallyformed on one side of the support by the following procedure.

—Formation of Organic Layer—

Trimethylolpropane triacrylate (product name “TMPTA”, manufactured byDaicel-Allnex Ltd.) and a photopolymerization initiator (trade name“ESACURE (registered trademark) KT046”, manufactured by Lamberti S.p.A.)were prepared and weighed in a mass ratio of 95:5, and these weredissolved in methyl ethyl ketone to prepare a coating liquid having asolid content concentration of 15%. This coating liquid was applied on aPET film in a roll to roll process using a die coater and passed througha drying zone at 50° C. for 3 minutes. Thereafter, the coated film wasirradiated with ultraviolet rays under a nitrogen atmosphere (cumulativeirradiation dose: about 600 mJ/cm²), cured by ultraviolet curing, andwound up. The thickness of the organic layer formed on the support was 1μm.

—Formation of Inorganic Layer—

Next, an inorganic layer (silicon nitride layer) was formed on thesurface of the organic layer by using a roll-to-roll CVD apparatus.Silane gas (flow rate: 160 sccm), ammonia gas (flow rate: 370 sccm),hydrogen gas (flow rate: 590 sccm), and nitrogen gas (flow rate: 240sccm) were used as raw material gases. As a power source, ahigh-frequency power source with a frequency of 13.56 MHz was used. Thefilm forming pressure was 40 Pa, and the film thickness reached was 50nm. In this manner, a barrier film was prepared in which an inorganiclayer was laminated on the surface of the organic layer formed on thesupport.

—Formation of Second Organic Layer—

Further, a second organic layer was laminated on the surface of theinorganic layer. For the second organic layer, 5.0 parts by mass of aphotopolymerization initiator (trade name “IRGACURE 184”, manufacturedby BASF Corporation) was weighed with respect to 95.0 parts by mass of aurethane skeleton acrylate polymer (trade name “ACRIT 8BR 930”,manufactured by Taisei Fine Chemical Co., Ltd.) and these materials weredissolved in methyl ethyl ketone to prepare a coating liquid having asolid content concentration of 15%.

This coating liquid was applied directly to the surface of the inorganiclayer in a roll-to-roll process using a die coater and passed through adrying zone at 100° C. for 3 minutes. Thereafter, the coated film wascured by irradiation with ultraviolet rays (cumulative irradiation doseof about 600 mJ/cm²) while being held by a heat roll heated to 60° C.,and wound up. The thickness of the second organic layer formed on thesupport was 0.1 μm.

In this manner, as the first substrate film and the second substratefilm, a barrier film with a second organic layer was prepared.

In the case where the oxygen permeability of this barrier film wasmeasured using OX-TRAN 2/20 (manufactured by MOCON Inc.), it showed avalue of 4.0×10⁻³ cc/(m²·day·atm) or less.

(Formation of Resin Layer)

As a coating liquid 1 for forming a resin layer, individual componentssuch as a curable compound, a polymerization initiator, and a silanecoupling agent were mixed by a tank or the like to prepare a coatingliquid.

—Composition of Coating Liquid 1 of Resin Layer—

Urethane (meth)acrylate 42 parts by mass (U-4HA, manufactured byShin-Nakamura Chemical Co., Ltd.) Tricyclodecane dimethanol diacrylate42 parts by mass (A-DCP, manufactured by Shin-Nakamura Chemical Co.,Ltd.) Flat alumina 15 parts by mass (Light scattering particles: SERAPH05070, manufactured by Kinsei Matec Co., Ltd.) Photopolymerizationinitiator  1 part by mass(IRGACURE TPO, manufactured by BASF Corporation)

—Formation of Resin Layer—

The coating liquid 1 for a resin layer was applied onto the firstsubstrate film, and the concave portions were transferred, followed byphotocuring to form a resin layer having a plurality of concaveportions. For the mold used for transfer, a corner portion of theconcave portion with roundness of radius of curvature of 10 μm was used.

Here, the concave portion had a regular hexagonal shape of a side of 125μm, a honeycomb like pattern, a depth h of the concave portion (thethickness of the bottom of the concave portion) of 40 μm, and a width t(line width) of 50 μm. That is, the aspect ratio h/t is 0.8.

Subsequently, the coating liquid for the resin layer was poured betweenthe first substrate film and a mold sheet and pressed with a laminatorat a pressure of 0.5 MPa to fill the concave portion of the mold sheetwith the resin, followed by photocuring. After curing, the mold sheetwas peeled off from the first substrate film to obtain a film having aplurality of concave portions. For photocuring, the resin layer wascured by irradiation with ultraviolet rays at a dose of 500 mJ/cm² fromthe first substrate film side using an air-cooled metal halide lamp(manufactured by Eye Graphics Co., Ltd.) at 200 W/cm.

The modulus of elasticity of the resin layer after curing was 4.2 GPa,as measured according to the standard of JIS K7161.

The width t (line width (50 μm)) is the shortest distance betweenadjacent fluorescent regions with the resin layer in between, that is,the thinnest part of the resin layer between the fluorescent regions.The permeability to oxygen at the resin layer thickness of 50 μm wasmeasured in the same manner as above, and was 8 cc/(m²·day·atm).

(Formation of Fluorescent Region and Adhesion of Substrate Film)

As a coating liquid 2 forming a fluorescent region, individualcomponents such as quantum dots, a curable compound, a polymerdispersant, a polymerization initiator, and a silane coupling agent weremixed by a tank or the like to prepare a coating liquid.

—Composition of Coating Liquid 2 for Fluorescent Region—

A quantum dot dispersion liquid having the following composition wasprepared to obtain a coating liquid 2.

Toluene dispersion liquid of quantum dots 1 (emission 20% by massmaximum: 520 nm) Toluene dispersion liquid of quantum dots 2 (emission 2% by mass maximum: 630 nm) Dicyclopentanyl acrylate 78.8% by mass  (DCP: FA-513AS, manufactured by Hitachi Chemical Co., Ltd.)Tricyclodecane dimethanol diacrylate 20% by mass (A-DCP, manufactured byShin-Nakamura Chemical Co., Ltd.) Light scattering particles 20% by mass(TOSPEARL 120, manufactured by Momentive Performance Materials Inc.)Photopolymerization initiator 0.2% by mass (IRGACURE TPO, manufactured by BASF Corporation)

For the quantum dots 1 and 2, nanocrystals having the followingcore-shell structure (InP/ZnS) were used.

-   -   Quantum dots 1: INP 530-10 (manufactured by NN-Labs, LLC)    -   Quantum dots 2: INP 620-10 (manufactured by NN-Labs, LLC)

—Application of Coating Liquid for Forming Fluorescent Region andAdhesion of Substrate Film—

The coating liquid 2 for forming a fluorescent region was applied onto aresin layer having a plurality of concave portions and a first substratefilm so that the concave portions were filled with the coating liquid 2,and a second substrate film was adhered and then pressed with alaminator at a pressure of 0.1 MPa, followed by photocuring to form afluorescent region-containing layer in which fluorescent regions wereformed in a plurality of concave portions of the resin layer, therebypreparing a phosphor-containing film.

For photocuring, the fluorescent region was cured by irradiation withultraviolet rays at a dose of 500 mJ/cm² from the first substrate filmside using an air-cooled metal halide lamp (manufactured by Eye GraphicsCo., Ltd.) at 200 W/cm.

The phosphor-containing layer of the obtained phosphor-containing filmwas set to have a thickness of 40 μm. The prepared film was cut with amicrotome, and the cross section of the section was observed with a SEM.The resulting thickness b at the bottom of the concave portion of theresin layer was 1.2 μm. The distance (the gap with the resin layer)between the surface of the second substrate film (the surface of thesecond organic layer) and the top surface of the concave portion of theresin layer was 0.5 μm.

Examples 2 to 12 and Comparative Examples 1 and 2

A phosphor-containing film was prepared in the same manner as in Example1, except that the thickness b of the bottom of the concave portion ofthe resin layer and the distance (the gap with the resin layer) betweenthe top surface of the concave portion of the resin layer and thesurface of the second substrate film (the surface of the second organiclayer) were changed by changing the pressure of the laminator at thetime of forming the resin layer and at the time of forming thefluorescent region as in Table 1.

In Example 12, the coating liquid 3 (quantum dot dispersion liquid) forthe fluorescent region having the following composition was prepared,and the coating liquid 3 was used as a coating liquid for thefluorescent region.

—Composition of Coating Liquid 3 for Fluorescent Region—

A quantum dot dispersion having the following composition was preparedto obtain a coating liquid 3.

Toluene dispersion liquid of quantum dots 1 20% by mass (emissionmaximum: 520 nm) Toluene dispersion liquid of quantum dots 2 2% by mass(emission maximum: 630 nm) Dicyclopentanyl acrylate 78.8% by mass (DCP:FA-513AS (manufactured by Hitachi Chemical Co., Ltd.) Tricyclodecanedimethanol diacrylate 20 parts by mass (A-DCP, manufactured byShin-Nakamura Chemical Co., Ltd.) Light scattering particles 20 parts bymass (TOSPEARL 120, manufactured by Momentive Performance MaterialsInc.) Photopolymerization initiator 0.2 part by mass(IRGACURE TPO, manufactured by BASF Corporation)

For the quantum dots 3 and 4, nanocrystals having the followingcore-shell structure (CdSe/ZnS) were used.

Quantum dots 1: CZ 520-10 (manufactured by NN-Labs, LLC)

Quantum dots 2: CZ 620-10 (manufactured by NN-Labs, LLC)

Comparative Example 3

The coating liquid 2 for the fluorescent region was sandwiched betweenthe first substrate film and the second substrate film without formingthe resin layer, and then photocured, such that a phosphor-containingfilm having no resin layer was prepared.

For photocuring, the coating liquid 2 for the fluorescent region wascured by irradiation with ultraviolet rays at a dose of 500 mJ/cm² fromthe first substrate film side using the air-cooled metal halide lamp(manufactured by Eye Graphics Co., Ltd.) at 200 W/cm to form thefluorescent region. The phosphor-containing layer of the obtainedphosphor-containing film was set to have a thickness of 30 μm.

<Evaluation Items>

The phosphor-containing films prepared in Examples and ComparativeExamples were wavelength converting members, and changes over time inthe luminescence performance of these wavelength converting members weremeasured and evaluated as follows.

Incidentally, each wavelength converting member was cut into apredetermined size using a Thomson blade MIR-CI23 manufactured byNakayama Corporation and used for each evaluation. Each side of the cutwavelength converting member straddles the resin layer and thefluorescent region.

(Initial Luminance)

A backlight unit was taken out by disassembling a commercially availabletablet terminal equipped with a blue light source in the backlight unit(trade name “Kindle (registered trademark) Fire HDX 7”, manufactured byAmazon, hereinafter sometimes simply referred to as Kindle Fire HDX 7).Instead of Quantum Dot Enhancement Film (QDEF), the wavelengthconversion film was incorporated into the backlight unit, each of awavelength converting members of Examples or Comparative Examples cutinto a rectangle was incorporated. In this manner, a liquid crystaldisplay was prepared.

The prepared liquid crystal display was turned on so that the wholesurface became white display and the luminance was measured with aluminance meter (trade name “SR3”, manufactured by Topcon Corporation)installed at a position 520 mm in the direction perpendicular to thesurface of the light guide plate It was measured.

The initial luminance Y₀ (cd/m²) was evaluated based on the followingevaluation standards.

—Evaluation Standards

-   -   A: Y₀≥530    -   B: 530>Y₀≥515    -   C: 515>Y₀≥500    -   D: 500>Y₀

(Evaluation of Moisture-Heat Resistance)

The prepared wavelength converting member was heated for 1000 hours at60° C. and 90% relative humidity using a precision thermostat DF411(manufactured by Yamato Scientific Co., Ltd.). Thereafter, in the samemanner as above, the wavelength converting member was incorporated intoKindle Fire HDX 7, the luminance was measured, and the relativeluminance Y_(W) after moisture-heat endurance with respect to theinitial luminance Y₀ was calculated. The relative luminance Y_(W) wasevaluated based on the following evaluation standards.

—Evaluation Standards—

A: Y_(W)≥95%

B: 95%>Y_(W)≥90%

C: 90%>Y_(W)≥80%

D: 80%>Y_(W)

(Evaluation of Peeling Force)

The manufactured wavelength converting member was cut into strips of 150mm in length and 25 mm in width, and a peeling force of F (N/25 mm) ofthe phosphor-containing layer of the first substrate film was measuredunder the conditions of the peeling angle of 180 degrees and the peelingrate of 300 mm/min according to JIS K6854 (T type peeling) and evaluatedbased on the following standards. In order to obtain a definite adhesionboundary, the measurement was performed by using a sample in which ananti-adhesion tape is attached to the first substrate film, where anon-adhering part of the sample serves as a gripping part.

—Evaluation Standards—

A: F≥10

B: 10>F≥3

C: 3>F≥1

D: 1>F

(Evaluation of End Portion Luminance Decrease)

In a room kept at 85° C., each wavelength converting member was placedon a commercially available blue light source (OPSM-H150X142Bmanufactured by OPTEX-FA Co., Ltd.) and the wavelength converting memberwas continuously irradiated with blue light for 1000 hours. After 1000hours, the phosphor-containing film was taken out, observed under anoptical microscope to evaluate the distance Lmm of the end portionluminance decrease (distance at which change in chromaticity orreduction in luminance can be confirmed).

—Evaluation Standards—

A: L≤0.5

B: 0.5<L≤1.0

C: 1.0<L≤1.5

D: 1.5<L

TABLE 1 Resin layer Thickness Gap to Fluorescent Evaluation of bottomLine Radius of resin region Peeling End portion Moisture- of concaveDepth width curvature layer QD particle force F luminance Luminance Y₀heat portion μm μm μm Pattern μm μm composition N/25 mm decrease mmcd/m² resistance Y_(w) Example 1 1.2 40 50 Regular 10 0.5 InP/ZnS A A AA hexagon Example 2 0.3 40 50 Regular 10 0.5 InP/ZnS A A A B hexagonExample 3 4.9 40 50 Regular 10 0.5 InP/ZnS A A A B hexagon Example 4 2.540 50 Regular 10 0.5 InP/ZnS A A B A hexagon Example 5 17.0 40 50Regular 10 0.5 InP/ZnS A A A A hexagon Example 6 17.0 40 50 Regular 100.5 InP/ZnS A A B A hexagon Example 7 1.2 40 50 Regular 10 1.7 InP/ZnS AB A B hexagon Example 8 1.2 40 50 Regular 10 3.8 InP/ZnS A B A B hexagonExample 9 1.2 40 50 Regular 10 12.1 InP/ZnS A B A B hexagon Example 101.2 40 50 Regular 10 <0.01 InP/ZnS B A A A hexagon Example 11 1.2 40 50Regular 10 0.09 InP/ZnS B A A A hexagon Example 12 1.2 40 50 Regular 100.5 CdSe/ZnS A A A A hexagon Comparative <0.1 40 50 Regular 10 0.5InP/ZnS A A A D Example 1 hexagon Comparative 25.0 40 50 Regular 10 0.5InP/ZnS A A C A Example 2 hexagon Comparative Having no resin layerInP/ZnS A D A C Example 3

From the results shown in Table 1, it is suggested that Examples of thepresent invention can provide a phosphor-containing film havingexcellent moisture-heat resistance and high reliability. Further, fromthe results of Examples and Comparative Example 1, it can be seen that,in the case where the thickness b of the bottom of the concave portionof the resin layer is too small, the end portion luminance decrease issuppressed, but the moisture-heat resistance deteriorates, and thereforeit can be seen that the main surface/the end face sealing of thephosphor-containing film is not compatible. Further, from the results ofExamples and Comparative Example 2, it can be seen that, in the casewhere the thickness b of the bottom of the concave portion of the resinlayer is too large, the luminance of the phosphor-containing film isdecreased. Further, from the results of Comparative Example 3, it can beseen that, in the case where the resin layer is not provided, thedurability deteriorates.

From the comparison between Example 1 and Examples 7 to 9, it can beseen, in the case where distance between the surface of the secondsubstrate film and the top surface of the concave portion of the resinlayer is short, durability is excellent.

Further, from the comparison between Example 1 and Examples 10 and 11,it can be seen, in a case where the distance between the surface of thesecond substrate film and the top surface of the concave portion of theresin layer is appropriately long, adhesiveness is excellent.

With respect to the phosphor-containing film according to the embodimentof the present invention, the wavelength converting member has beendescribed as an example in the foregoing embodiments, but appropriateselection of the type of the phosphor can provide applications for anorganic electroluminescence layer in an organic electroluminescenceelement, an organic photoelectric conversion layer in an organic solarcell, or the like, and can achieve an effect of suppressing performancedeterioration.

Explanation of References

-   -   1, 3, 4, 6: phosphor-containing film    -   10: first substrate film    -   11, 21: support film    -   12, 22: barrier layer    -   20: second substrate film    -   30: phosphor-containing layer    -   31, 31 a, 31 b, 31 e: phosphors    -   33: binder    -   35, 35 a, 35 b: region containing phosphors (fluorescent region)    -   37: coating liquid for resin layer    -   38: resin layer having impermeability to oxygen    -   100: wavelength converting member    -   101A: light source    -   101B: light guide plate    -   101C: planar light source    -   102: backlight unit    -   102A: reflecting plate    -   102B: retroreflective member    -   103: liquid crystal cell unit    -   104: liquid crystal display    -   110: liquid crystal cell    -   120, 130: polarizing plate    -   121, 123, 131, 133: polarizing plate protective film    -   122, 132: polarizer

What is claimed is:
 1. A phosphor-containing film comprising: aphosphor-containing layer having a resin layer which has impermeabilityto oxygen and is provided with a plurality of discretely arrangedconcave portions, and a plurality of fluorescent regions, each of whichis arranged in the concave portion formed in the resin layer; and afirst substrate film laminated on one main surface of thephosphor-containing layer and a second substrate film laminated on theother main surface of the phosphor-containing layer, wherein thefluorescent regions contain the phosphor that deteriorates through areaction with oxygen in the case of being exposed to oxygen, and abinder, the first substrate film includes a support film, and aninorganic layer provided on a surface of the support film on a sidefacing the phosphor-containing layer, the resin layer has a modulus ofelasticity of 0.5 to 10 GPa, and a thickness of a bottom of the concaveportion of the resin layer is 0.1 to 20 μm.
 2. The phosphor-containingfilm according to claim 1, wherein the second substrate film includes asupport film, and an inorganic layer provided on a surface of thesupport film on a side facing the phosphor-containing layer, and theinorganic layer of the second substrate film and the top surface of theconcave portion of the resin layer are not in contact with each other.3. The phosphor-containing film according to claim 1, wherein a depth hof the concave portion of the resin layer is 10 to 80 μm, and a width tbetween the adjacent fluorescent regions is 5 to 300 μm.
 4. Thephosphor-containing film according to claim 1, wherein the resin layerhas an oxygen permeability of 10 cc/(m²·day·atm) or less.
 5. Thephosphor-containing film according to claim 1, wherein the firstsubstrate film and the second substrate film have an oxygen permeabilityof 1 cc/(m²·day·atm) or less.
 6. The phosphor-containing film accordingto claim 1, wherein in the phosphor-containing layer, the fluorescentregion is surrounded by the resin layer and a fluorescent regionincluding a phosphor which has deteriorated through a reaction withoxygen by exposure to oxygen.
 7. A backlight unit comprising: awavelength converting member including the phosphor-containing filmaccording to claim 1; and at least one of a blue light emitting diode oran ultraviolet light emitting diode.